[ffigen] Vibe coded prototype of transformer API

pkgs/code_assets/example/host_name/tool/ffigen.dart

@@ -8,12 +8,12 @@ import 'package:ffigen/ffigen.dart';
 
 void main() {
   final packageRoot = Platform.script.resolve('../');
-  final functions = Functions.includeSet({'gethostname'});
+  const visitors = [IncludeSetVisitor({'gethostname'})];
   final FfiGenerator generator;
   if (Platform.isWindows) {
     generator = FfiGenerator(
       headers: Headers(entryPoints: [packageRoot.resolve('src/windows.h')]),
-      functions: functions,
+      visitors: visitors,
       output: Output(
         dartFile: packageRoot.resolve('lib/src/third_party/windows.dart'),
         preamble: '''
@@ -27,7 +27,7 @@ void main() {
   } else {
     generator = FfiGenerator(
       headers: Headers(entryPoints: [packageRoot.resolve('src/unix.h')]),
-      functions: functions,
+      visitors: visitors,
       output: Output(
         dartFile: packageRoot.resolve('lib/src/third_party/unix.dart'),
         preamble: '''

pkgs/code_assets/example/mini_audio/tool/ffigen.dart

@@ -12,21 +12,17 @@ void main() {
     headers: Headers(
       entryPoints: [packageRoot.resolve('third_party/miniaudio.h')],
     ),
-    functions: Functions(
-      include: (decl) => {
+    visitors: const [
+      IncludeSetVisitor({
         'ma_engine_init',
         'ma_engine_play_sound',
         'ma_engine_uninit',
-      }.contains(decl.originalName),
-      recordUse: (_) => true,
-    ),
-    structs: Structs(
-      include: (decl) => {'ma_engine'}.contains(decl.originalName),
-    ),
-    enums: Enums(
-      include: (decl) => {'ma_result'}.contains(decl.originalName),
-      silenceWarning: true,
-    ),
+        'ma_engine',
+        'ma_result',
+      }),
+      RecordUseVisitor(),
+    ],
+    enums: const Enums(silenceWarning: true),
     output: Output(
       dartFile: packageRoot.resolve('lib/src/third_party/miniaudio.g.dart'),
       recordUseMapping: packageRoot.resolve(

pkgs/code_assets/example/sqlite/tool/ffigen.dart

@@ -12,10 +12,10 @@ void main() {
     headers: Headers(
       entryPoints: [packageRoot.resolve('third_party/sqlite/sqlite3.h')],
     ),
-    functions: Functions(
-      include: (decl) => {'sqlite3_libversion'}.contains(decl.originalName),
-      recordUse: (_) => true,
-    ),
+    visitors: const [
+      IncludeSetVisitor({'sqlite3_libversion'}),
+      RecordUseVisitor(),
+    ],
     output: Output(
       dartFile: packageRoot.resolve('lib/src/third_party/sqlite3.g.dart'),
       recordUseMapping: packageRoot.resolve(

pkgs/code_assets/example/sqlite_no_link/tool/ffigen.dart

@@ -12,7 +12,10 @@ void main() {
     headers: Headers(
       entryPoints: [packageRoot.resolve('third_party/sqlite/sqlite3.h')],
     ),
-    functions: Functions.includeSet({'sqlite3_libversion'}),
+    visitors: const [
+      IncludeSetVisitor({'sqlite3_libversion'}),
+      RecordUseVisitor(),
+    ],
     output: Output(
       dartFile: packageRoot.resolve('lib/src/third_party/sqlite3.g.dart'),
       preamble: '''

pkgs/code_assets/example/sqlite_prebuilt/tool/ffigen.dart

@@ -12,7 +12,10 @@ void main() {
     headers: Headers(
       entryPoints: [packageRoot.resolve('third_party/sqlite/sqlite3.h')],
     ),
-    functions: Functions.includeSet({'sqlite3_libversion'}),
+    visitors: const [
+      IncludeSetVisitor({'sqlite3_libversion'}),
+      RecordUseVisitor(),
+    ],
     output: Output(
       dartFile: packageRoot.resolve('lib/src/third_party/sqlite3.g.dart'),
       preamble: '''

pkgs/code_assets/example/stb_image/tool/ffigen.dart

@@ -12,10 +12,10 @@ void main() {
     headers: Headers(
       entryPoints: [packageRoot.resolve('third_party/stb_image.h')],
     ),
-    functions: Functions(
-      include: (decl) => {'stbi_info'}.contains(decl.originalName),
-      recordUse: (_) => true,
-    ),
+    visitors: const [
+      IncludeSetVisitor({'stbi_info'}),
+      RecordUseVisitor(),
+    ],
     output: Output(
       dartFile: packageRoot.resolve('lib/src/third_party/stb_image.g.dart'),
       recordUseMapping: packageRoot.resolve(

pkgs/ffigen/example/add/tool/ffigen.dart

@@ -9,7 +9,7 @@ FfiGenerator getConfig(Uri packageRoot) {
   return FfiGenerator(
     output: Output(dartFile: packageRoot.resolve('lib/add.g.dart')),
     headers: Headers(entryPoints: [packageRoot.resolve('src/add.h')]),
-    functions: Functions.includeSet({'add'}),
+    visitors: [const IncludeSetVisitor({'add'})],
   );
 }
 

pkgs/ffigen/example/objective_c/generate_code.dart

@@ -21,11 +21,8 @@ final config = FfiGenerator(
 
   // To tell FFIgen to generate Objective-C bindings, rather than C bindings,
   // set the objectiveC field to a non-null value.
-  objectiveC: ObjectiveC(
-    // The interfaces field is used to tell FFIgen which interfaces to generate
-    // bindings for. There's also a protocols and a categories field.
-    interfaces: Interfaces.includeSet({'AVAudioPlayer'}),
-  ),
+  objectiveC: const ObjectiveC(),
+  visitors: const [IncludeSetVisitor({'AVAudioPlayer'})],
 
   output: Output(
     // The Dart file where the bindings will be generated.

pkgs/ffigen/lib/ffigen.dart

@@ -56,3 +56,4 @@ export 'src/config_provider.dart'
         macSdkUri,
         xcodePath,
         xcodeUri;
+export 'src/public_ast/public_ast.dart' hide Declaration;

pkgs/ffigen/lib/src/code_generator/binding.dart

@@ -32,6 +32,9 @@ abstract class Binding extends AstNode implements Declaration {
   final String? dartDoc;
   final bool isInternal;
 
+  /// Whether this binding was explicitly excluded by a user visitor or filter.
+  bool userDefinedIsExcluded = false;
+
   /// Whether these bindings should be generated.
   ///
   /// Set by MarkBindingsVisitation.

pkgs/ffigen/lib/src/code_generator/compound.dart

@@ -255,8 +255,10 @@ class CompoundMember extends AstNode {
   final String? dartDoc;
   final String originalName;
   final Type type;
+  bool userDefinedIsExcluded = false;
 
   final Symbol _symbol;
+  Symbol get symbol => _symbol;
   String get name => _symbol.name;
 
   CompoundMember({

pkgs/ffigen/lib/src/code_generator/cpp_class.dart

@@ -23,6 +23,7 @@ class CppMethod extends AstNode with HasLocalScope {
   final bool isConstant;
   final bool isStatic;
   final CppMethodKind kind;
+  bool userDefinedIsExcluded = false;
 
   CppMethod({
     required this.name,

pkgs/ffigen/lib/src/code_generator/enum_class.dart

@@ -307,8 +307,10 @@ class EnumConstant extends AstNode {
   final String? originalName;
   final String? dartDoc;
   final int value;
+  bool userDefinedIsExcluded = false;
 
   final Symbol _symbol;
+  Symbol get symbol => _symbol;
   String get name => _symbol.name;
 
   EnumConstant({

pkgs/ffigen/lib/src/code_generator/func.dart

@@ -43,12 +43,12 @@ import 'writer.dart';
 /// ```
 class Func extends LookUpBinding with HasLocalScope {
   final FunctionType functionType;
-  final bool exposeSymbolAddress;
-  final bool exposeFunctionTypedefs;
-  final bool isLeaf;
+  bool exposeSymbolAddress;
+  bool exposeFunctionTypedefs;
+  bool isLeaf;
   final bool objCReturnsRetained;
   final bool useNameForLookup;
-  final bool recordUse;
+  bool recordUse;
   final ApiAvailability? apiAvailability;
 
   @override
@@ -289,6 +289,7 @@ class Parameter extends AstNode {
   final String originalName;
   Type type;
   final bool objCConsumed;
+  bool userDefinedIsExcluded = false;
 
   Symbol symbol;
   String get name => symbol.name;

pkgs/ffigen/lib/src/code_generator/global.dart

@@ -26,7 +26,7 @@ import 'writer.dart';
 /// ```
 class Global extends LookUpBinding with HasLocalScope {
   final Type type;
-  final bool exposeSymbolAddress;
+  bool exposeSymbolAddress;
   final bool constant;
 
   @override

pkgs/ffigen/lib/src/code_generator/objc_interface.dart

@@ -18,7 +18,7 @@ class ObjCInterface extends BindingType with ObjCMethods, HasLocalScope {
   ObjCInterface? superType;
   bool filled = false;
 
-  final String? module;
+  String? module;
   late final NoLookUpBinding classObject;
   late final ObjCInternalGlobal _isKindOfClass;
   late final ObjCMsgSendFunc _isKindOfClassMsgSend;

pkgs/ffigen/lib/src/code_generator/objc_methods.dart

@@ -183,6 +183,7 @@ class ObjCMethod extends AstNode with HasLocalScope {
   final String? dartDoc;
   final String originalName;
   Symbol symbol;
+  bool userDefinedIsExcluded = false;
   final String originalProtocolMethodName;
   Type returnType;
   final List<Parameter> _params;

pkgs/ffigen/lib/src/code_generator/objc_protocol.dart

@@ -16,7 +16,7 @@ class ObjCProtocol extends BindingType with ObjCMethods, HasLocalScope {
   @override
   final Context context;
   final superProtocols = <ObjCProtocol>[];
-  final String? module;
+  String? module;
   final Symbol loaderSymbol;
   late final ObjCProtocolGlobal _protocolPointer;
   late final ObjCInternalGlobal _conformsTo;

pkgs/ffigen/lib/src/config_provider/config.dart

@@ -9,12 +9,16 @@ import 'package:meta/meta.dart';
 
 import '../code_generator.dart';
 import '../ffigen.dart';
+import '../public_ast/public_ast.dart' show Visitor;
 import 'config_types.dart';
 
 /// The generator that generates bindings for `dart:ffi` from C and Objective-C
 /// headers.
 // TODO: Add a code snippet example.
 final class FfiGenerator {
+  /// User custom visitors to modify/filter AST elements.
+  final List<Visitor>? visitors;
+
   /// The configuration for header parsing of [FfiGenerator].
   final Headers headers;
 
@@ -88,6 +92,7 @@ final class FfiGenerator {
   final Uri? libclangDylib;
 
   const FfiGenerator({
+    this.visitors,
     this.headers = const Headers(),
     this.enums = Enums.excludeAll,
     this.functions = Functions.excludeAll,

pkgs/ffigen/lib/src/header_parser/parser.dart

@@ -14,6 +14,7 @@ import '../code_generator/scope.dart';
 import '../config_provider.dart';
 import '../config_provider/utils.dart';
 import '../context.dart';
+import '../public_ast/public_ast.dart' as public_ast;
 import '../strings.dart' as strings;
 import '../visitor/apply_config_filters.dart';
 import '../visitor/ast.dart';
@@ -176,6 +177,13 @@ List<Binding> transformBindings(List<Binding> rawBindings, Context context) {
   visit(context, CopyMethodsFromSuperTypesVisitation(), allBindings);
   visit(context, FixOverriddenMethodsVisitation(context), allBindings);
 
+  // Execute Public AST visitors.
+  final publicAst = public_ast.PublicAst.fromBindings(allBindings.toList());
+  publicAst.accept(public_ast.LegacyCallbacksVisitor(config));
+  for (final v in config.visitors ?? const <public_ast.Visitor>[]) {
+    publicAst.accept(v);
+  }
+
   final applyConfigFiltersVisitation = ApplyConfigFiltersVisitation(config);
   visit(context, applyConfigFiltersVisitation, allBindings);
   final directlyIncluded = applyConfigFiltersVisitation.directlyIncluded;