[ffigen] Remove headers from BindingIndex

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

@@ -1156,6 +1156,19 @@ class Clang {
   late final _clang_getCursorDefinition = _clang_getCursorDefinitionPtr
       .asFunction<CXCursor Function(CXCursor)>();
 
+  /// Determine whether the declaration pointed to by this cursor
+  /// is also a definition of that entity.
+  int clang_isCursorDefinition(CXCursor arg0) {
+    return _clang_isCursorDefinition(arg0);
+  }
+
+  late final _clang_isCursorDefinitionPtr =
+      _lookup<ffi.NativeFunction<ffi.UnsignedInt Function(CXCursor)>>(
+        'clang_isCursorDefinition',
+      );
+  late final _clang_isCursorDefinition = _clang_isCursorDefinitionPtr
+      .asFunction<int Function(CXCursor)>();
+
   /// Given a cursor that represents a property declaration, return the
   /// associated property attributes. The bits are formed from
   /// \c CXObjCPropertyAttrKind.

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

@@ -20,10 +20,13 @@ Set<Binding> parseTranslationUnit(
 ) {
   final bindings = <Binding>{};
   final logger = context.logger;
+  final headers = <String, bool>{};
 
   translationUnitCursor.visitChildren((cursor) {
-    try {
-      if (shouldIncludeRootCursor(context, cursor.sourceFileName())) {
+    final file = cursor.sourceFileName();
+    if (file.isEmpty) return;
+    if (headers[file] ??= context.config.shouldIncludeHeader(Uri.file(file))) {
+      try {
         logger.finest('rootCursorVisitor: ${cursor.completeStringRepr()}');
         switch (clang.clang_getCursorKind(cursor)) {
           case clang_types.CXCursorKind.CXCursor_FunctionDecl:
@@ -57,15 +60,15 @@ Set<Binding> parseTranslationUnit(
           default:
             logger.finer('rootCursorVisitor: CursorKind not implemented');
         }
-      } else {
-        logger.finest(
-          'rootCursorVisitor:(not included) ${cursor.completeStringRepr()}',
-        );
+      } catch (e, s) {
+        logger.severe(e);
+        logger.severe(s);
+        rethrow;
       }
-    } catch (e, s) {
-      logger.severe(e);
-      logger.severe(s);
-      rethrow;
+    } else {
+      logger.finest(
+        'rootCursorVisitor:(not included) ${cursor.completeStringRepr()}',
+      );
     }
   });
 
@@ -104,22 +107,3 @@ void buildUsrCursorDefinitionMap(
     }
   });
 }
-
-/// True if a cursor should be included based on headers config, used on root
-/// declarations.
-bool shouldIncludeRootCursor(Context context, String sourceFile) {
-  // Handle empty string in case of system headers or macros.
-  if (sourceFile.isEmpty) {
-    return false;
-  }
-
-  // Add header to seen if it's not.
-  if (!context.bindingsIndex.isSeenHeader(sourceFile)) {
-    context.bindingsIndex.addHeaderToSeen(
-      sourceFile,
-      context.config.shouldIncludeHeader(Uri.file(sourceFile)),
-    );
-  }
-
-  return context.bindingsIndex.getSeenHeaderStatus(sourceFile)!;
-}

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

@@ -85,6 +85,10 @@ extension CXSourceRangePtrExt on Pointer<clang_types.CXSourceRange> {
 }
 
 extension CXCursorExt on clang_types.CXCursor {
+  bool get isNull => clang.clang_Cursor_isNull(this) != 0;
+  bool get isDefinition => clang.clang_isCursorDefinition(this) != 0;
+  clang_types.CXCursor get definition => clang.clang_getCursorDefinition(this);
+
   String usr() {
     var res = clang.clang_getCursorUSR(this).toStringAndDispose();
     if (isAnonymousRecordDecl()) {
@@ -471,14 +475,6 @@ extension DynamicCStringArray on Pointer<Pointer<Utf8>> {
   }
 }
 
-class Stack<T> {
-  final _stack = <T>[];
-
-  T get top => _stack.last;
-  T pop() => _stack.removeLast();
-  void push(T item) => _stack.add(item);
-}
-
 class Macro {
   final String usr;
   final String? originalName;
@@ -501,9 +497,6 @@ class BindingsIndex {
   /// Contains usr for typedefs which cannot be generated.
   final Set<String> _unsupportedTypealiases = {};
 
-  /// Index for headers.
-  final Map<String, bool> _headerCache = {};
-
   bool isSeenType(String usr) => _declaredTypes.containsKey(usr);
   void addTypeToSeen(String usr, Type type) => _declaredTypes[usr] = type;
   Type? getSeenType(String usr) => _declaredTypes[usr];
@@ -523,10 +516,6 @@ class BindingsIndex {
       _unsupportedTypealiases.contains(usr);
   void addUnsupportedTypealiasToSeen(String usr) =>
       _unsupportedTypealiases.add(usr);
-  bool isSeenHeader(String source) => _headerCache.containsKey(source);
-  void addHeaderToSeen(String source, bool includeStatus) =>
-      _headerCache[source] = includeStatus;
-  bool? getSeenHeaderStatus(String source) => _headerCache[source];
   void addObjCBlockToSeen(String key, ObjCBlock t) => _objcBlocks[key] = t;
   ObjCBlock? getSeenObjCBlock(String key) => _objcBlocks[key];
   void addObjCProtocolToSeen(String usr, ObjCProtocol t) =>

pkgs/ffigen/tool/libclang_config.yaml

@@ -120,6 +120,7 @@ functions:
     - clang_getFieldDeclBitWidth
     - clang_Cursor_isFunctionInlined
     - clang_getCursorDefinition
+    - clang_isCursorDefinition
     - clang_getCursorAvailability
     - clang_getCursorPlatformAvailability
     - clang_disposeCXPlatformAvailability