[ffigen] Remove Constant from public AST

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

@@ -11,7 +11,7 @@ import 'scope.dart';
 import 'utils.dart';
 import 'writer.dart';
 
-/// A simple Constant.
+/// Base class for constants.
 ///
 /// Expands to -
 /// ```dart
@@ -22,7 +22,7 @@ import 'writer.dart';
 /// ```dart
 /// const int name = 10;
 /// ```
-class Constant extends NoLookUpBinding {
+abstract class Constant extends NoLookUpBinding {
   /// The rawType is pasted as it is. E.g 'int', 'String', 'double'
   final String rawType;
 
@@ -62,12 +62,6 @@ class Constant extends NoLookUpBinding {
       string: s.toString(),
     );
   }
-
-  @override
-  public_ast.AstNode? toPublicAstNode() => public_ast.Constant(this);
-
-  @override
-  void visit(Visitation visitation) => visitation.visitConstant(this);
 }
 
 /// A [Constant] defined by an unnamed enum.

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

@@ -29,12 +29,15 @@ class Global extends LookUpBinding with HasLocalScope {
   final Type type;
   final bool exposeSymbolAddress;
   final bool constant;
+  final ConstantValue? constantValue;
 
   @override
   final bool loadFromNativeAsset;
 
   bool isIncluded = false;
 
+  bool get isConst => constantValue != null && !exposeSymbolAddress;
+
   Global({
     super.usr,
     super.originalName,
@@ -43,6 +46,7 @@ class Global extends LookUpBinding with HasLocalScope {
     super.dartDoc,
     this.exposeSymbolAddress = false,
     this.constant = false,
+    this.constantValue,
     this.loadFromNativeAsset = false,
   }) : super(symbol: Symbol(name, SymbolKind.field));
 
@@ -54,6 +58,16 @@ class Global extends LookUpBinding with HasLocalScope {
     final s = StringBuffer();
     final globalVarName = name;
     s.write(makeDartDoc(dartDoc));
+    if (isConst) {
+      s.write(
+        'const ${constantValue!.type} $globalVarName = '
+        '${constantValue!.value};\n\n',
+      );
+      return BindingString(
+        type: BindingStringType.global,
+        string: s.toString(),
+      );
+    }
     final context = w.context;
     final dartType = type.getDartType(context);
     final ffiDartType = type.getFfiDartType(context);
@@ -173,6 +187,7 @@ class Global extends LookUpBinding with HasLocalScope {
   @override
   void visitChildren(Visitor visitor) {
     super.visitChildren(visitor);
+    if (isConst) return;
     visitor.visit(type);
     visitor.visit(ffiImport);
     if (loadFromNativeAsset && exposeSymbolAddress) {
@@ -183,3 +198,11 @@ class Global extends LookUpBinding with HasLocalScope {
   @override
   void visit(Visitation visitation) => visitation.visitGlobal(this);
 }
+
+/// A constant value for a [Global].
+class ConstantValue {
+  final String type;
+  final String value;
+
+  const ConstantValue({required this.type, required this.value});
+}

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

@@ -55,22 +55,27 @@ class Library {
     // Seperate bindings which require lookup.
     final lookupBindings = <LookUpBinding>[];
     final nativeBindings = <LookUpBinding>[];
+    final noLookUpBindings = <Binding>[];
     String? nativeAssetId;
 
     final outputStyle = context.config.output.style;
     final outputStyleAssetId = outputStyle is NativeExternalBindings
         ? outputStyle.assetId
         : null;
 
-    for (final binding in bindings.whereType<LookUpBinding>()) {
-      final loadFromNativeAsset = binding.loadFromNativeAsset;
+    for (final binding in bindings) {
+      // All LookUpBindings are look-up bindings, except const Globals.
+      if (binding is LookUpBinding && !(binding is Global && binding.isConst)) {
+        final loadFromNativeAsset = binding.loadFromNativeAsset;
 
-      // At the moment, all bindings share their native config.
-      if (loadFromNativeAsset) nativeAssetId = outputStyleAssetId;
+        // At the moment, all bindings share their native config.
+        if (loadFromNativeAsset) nativeAssetId = outputStyleAssetId;
 
-      (loadFromNativeAsset ? nativeBindings : lookupBindings).add(binding);
+        (loadFromNativeAsset ? nativeBindings : lookupBindings).add(binding);
+      } else {
+        noLookUpBindings.add(binding);
+      }
     }
-    final noLookUpBindings = bindings.whereType<NoLookUpBinding>().toList();
     final hasNoLookupNativeHelper = noLookUpBindings.any(
       (b) => b.hasNativeHelperFunctions,
     );

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

@@ -226,7 +226,7 @@ const _\$objcVersionCheck = $objcPrefix.ObjCVersionCheck(
 
     // Warn for macros.
     final hasMacroBindings = bindings.any(
-      (element) => element is Constant && element.usr.contains('@macro@'),
+      (element) => element is MacroConstant,
     );
     if (hasMacroBindings) {
       context.logger.info(
@@ -237,8 +237,7 @@ const _\$objcVersionCheck = $objcPrefix.ObjCVersionCheck(
 
     // Remove internal bindings and macros.
     bindings.removeWhere((element) {
-      return element.isInternal ||
-          (element is Constant && element.usr.contains('@macro@'));
+      return element.isInternal || (element is MacroConstant);
     });
 
     // Sort bindings alphabetically by USR.

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

@@ -196,32 +196,6 @@ class Global extends DeclNode {
   set isIncluded(bool value) => _global.isIncluded = value;
 }
 
-/// A C constant declaration.
-class Constant extends DeclNode {
-  final internal.Constant _constant;
-
-  Constant(this._constant);
-
-  @override
-  void accept(Visitor visitor) => visitor.visitConstant(this);
-
-  @override
-  String get usr => _constant.usr;
-
-  @override
-  String get originalName => _constant.originalName;
-
-  @override
-  String get name => _constant.symbol.oldName;
-
-  @override
-  set name(String value) => _constant.symbol.oldName = value;
-
-  /// Whether this Constant should be included in code generation.
-  bool get isIncluded => _constant.isIncluded;
-  set isIncluded(bool value) => _constant.isIncluded = value;
-}
-
 /// A C macro constant declaration.
 class MacroConstant extends DeclNode {
   final internal.MacroConstant _macro;

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

@@ -73,7 +73,6 @@ abstract base class Visitor {
     void Function(Union) union,
     void Function(EnumClass) enumClass,
     void Function(Global) global,
-    void Function(Constant) constant,
     void Function(MacroConstant) macroConstant,
     void Function(Typealias) typealias,
     void Function(ObjCInterface) objCInterface,
@@ -99,7 +98,6 @@ abstract base class Visitor {
   void visitUnion(Union node) {}
   void visitEnum(EnumClass node) {}
   void visitGlobal(Global node) {}
-  void visitConstant(Constant node) {}
   void visitMacro(MacroConstant node) {}
   void visitTypealias(Typealias node) {}
   void visitObjCInterface(ObjCInterface node) {}
@@ -120,7 +118,6 @@ final class _CallbackVisitor extends Visitor {
   final void Function(Union) _union;
   final void Function(EnumClass) _enumClass;
   final void Function(Global) _global;
-  final void Function(Constant) _constant;
   final void Function(MacroConstant) _macroConstant;
   final void Function(Typealias) _typealias;
   final void Function(ObjCInterface) _objCInterface;
@@ -140,7 +137,6 @@ final class _CallbackVisitor extends Visitor {
     void Function(Union) union = _defaultVisit,
     void Function(EnumClass) enumClass = _defaultVisit,
     void Function(Global) global = _defaultVisit,
-    void Function(Constant) constant = _defaultVisit,
     void Function(MacroConstant) macroConstant = _defaultVisit,
     void Function(Typealias) typealias = _defaultVisit,
     void Function(ObjCInterface) objCInterface = _defaultVisit,
@@ -158,7 +154,6 @@ final class _CallbackVisitor extends Visitor {
        _union = union,
        _enumClass = enumClass,
        _global = global,
-       _constant = constant,
        _macroConstant = macroConstant,
        _typealias = typealias,
        _objCInterface = objCInterface,
@@ -190,9 +185,6 @@ final class _CallbackVisitor extends Visitor {
   @override
   void visitGlobal(Global node) => _global(node);
 
-  @override
-  void visitConstant(Constant node) => _constant(node);
-
   @override
   void visitMacro(MacroConstant node) => _macroConstant(node);
 

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

@@ -1373,14 +1373,6 @@ final class YamlConfigAstVisitor extends public_ast.Visitor {
     }
   }
 
-  @override
-  void visitConstant(public_ast.Constant node) {
-    node.isIncluded = config.globals.shouldInclude(_decl(node));
-    if (config.globals.rename(_decl(node)) case final rename?) {
-      node.name = rename;
-    }
-  }
-
   @override
   void visitMacro(public_ast.MacroConstant node) {
     node.isIncluded = config.macroDecl.shouldInclude(_decl(node));

pkgs/ffigen/lib/src/context.dart

@@ -22,7 +22,7 @@ class Context {
   final CursorIndex cursorIndex;
   final bindingsIndex = BindingsIndex();
   final savedMacros = <String, Macro>{};
-  final unnamedEnumConstants = <Constant>[];
+  final unnamedEnumConstants = <UnnamedEnumConstant>[];
   late final ObjCBuiltInFunctions objCBuiltInFunctions;
   bool hasSourceErrors = false;
   final reportedCommentRanges = <((String, int), (String, int))>{};

pkgs/ffigen/lib/src/header_parser/sub_parsers/unnamed_enumdecl_parser.dart

@@ -9,9 +9,12 @@ import '../utils.dart';
 import 'api_availability.dart';
 
 /// Saves unnamed enums.
-List<Constant> saveUnNamedEnum(Context context, clang_types.CXCursor cursor) {
+List<UnnamedEnumConstant> saveUnNamedEnum(
+  Context context,
+  clang_types.CXCursor cursor,
+) {
   final logger = context.logger;
-  final addedConstants = <Constant>[];
+  final addedConstants = <UnnamedEnumConstant>[];
   cursor.visitChildren((child) {
     try {
       logger.finest(
@@ -40,7 +43,7 @@ List<Constant> saveUnNamedEnum(Context context, clang_types.CXCursor cursor) {
 }
 
 /// Adds the parameter to func in functiondecl_parser.dart.
-Constant? _addUnNamedEnumConstant(
+UnnamedEnumConstant? _addUnNamedEnumConstant(
   Context context,
   clang_types.CXCursor cursor,
 ) {

pkgs/ffigen/lib/src/header_parser/sub_parsers/var_parser.dart

@@ -21,65 +21,34 @@ Binding? parseVarDeclaration(Context context, clang_types.CXCursor cursor) {
   if (bindingsIndex.isSeenGlobalVar(usr)) {
     return bindingsIndex.getSeenGlobalVar(usr);
   }
-  if (bindingsIndex.isSeenVariableConstant(usr)) {
-    return bindingsIndex.getSeenVariableConstant(usr);
-  }
 
   final decl = Declaration(usr: usr, originalName: name);
   final cType = cursor.type();
 
-  // Try to evaluate as a constant first,
-  // unless the config asks for the variable's address.
-  if (cType.isConstQualified && !config.globals.includeSymbolAddress(decl)) {
+  ConstantValue? constantValue;
+  if (cType.isConstQualified) {
     final evalResult = clang.clang_Cursor_Evaluate(cursor);
     final evalKind = clang.clang_EvalResult_getKind(evalResult);
-    Constant? constant;
 
     switch (evalKind) {
       case clang_types.CXEvalResultKind.CXEval_Int:
         final value = clang.clang_EvalResult_getAsLongLong(evalResult);
-        constant = Constant(
-          usr: usr,
-          originalName: name,
-          name: name,
-          dartDoc: getCursorDocComment(context, cursor),
-          rawType: 'int',
-          rawValue: value.toString(),
-        );
+        constantValue = ConstantValue(type: 'int', value: value.toString());
         break;
       case clang_types.CXEvalResultKind.CXEval_Float:
         final value = clang.clang_EvalResult_getAsDouble(evalResult);
-        constant = Constant(
-          usr: usr,
-          originalName: name,
-          name: name,
-          dartDoc: getCursorDocComment(context, cursor),
-          rawType: 'double',
-          rawValue: writeDoubleAsString(value),
+        constantValue = ConstantValue(
+          type: 'double',
+          value: writeDoubleAsString(value),
         );
         break;
       case clang_types.CXEvalResultKind.CXEval_StrLiteral:
         final value = clang.clang_EvalResult_getAsStr(evalResult);
         final rawValue = getWrittenStringRepresentation(name, value, context);
-        constant = Constant(
-          usr: usr,
-          originalName: name,
-          name: name,
-          dartDoc: getCursorDocComment(context, cursor),
-          rawType: 'String',
-          rawValue: "'$rawValue'",
-        );
+        constantValue = ConstantValue(type: 'String', value: "'$rawValue'");
         break;
     }
     clang.clang_EvalResult_dispose(evalResult);
-
-    if (constant != null) {
-      logger.fine(
-        '++++ Adding Constant from Global: ${cursor.completeStringRepr()}',
-      );
-      bindingsIndex.addVariableConstantToSeen(usr, constant);
-      return constant;
-    }
   }
 
   logger.fine('++++ Adding Global: ${cursor.completeStringRepr()}');
@@ -107,6 +76,7 @@ Binding? parseVarDeclaration(Context context, clang_types.CXCursor cursor) {
     dartDoc: getCursorDocComment(context, cursor),
     exposeSymbolAddress: config.globals.includeSymbolAddress(decl),
     constant: cType.isConstQualified,
+    constantValue: constantValue,
     loadFromNativeAsset: nativeOutputStyle,
   );
   bindingsIndex.addGlobalVarToSeen(usr, global);

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

@@ -516,10 +516,9 @@ class Macro {
 class BindingsIndex {
   // Tracks if bindings are already seen, Map key is USR obtained from libclang.
   final Map<String, Func> _functions = {};
-  final Map<String, Constant> _unnamedEnumConstants = {};
+  final Map<String, UnnamedEnumConstant> _unnamedEnumConstants = {};
   final Map<String, String> _macros = {};
   final Map<String, Global> _globals = {};
-  final Map<String, Constant> _variableConstants = {};
   final Map<String, Typealias> _typealiases = {};
   final Map<String, EnumClass> _enums = {};
   final Map<String, Compound> _compounds = {};
@@ -535,18 +534,15 @@ class BindingsIndex {
   bool isSeenFunc(String usr) => _functions.containsKey(usr);
   void addFuncToSeen(String usr, Func func) => _functions[usr] = func;
   Func? getSeenFunc(String usr) => _functions[usr];
-  void addUnnamedEnumConstantToSeen(String usr, Constant enumConstant) =>
-      _unnamedEnumConstants[usr] = enumConstant;
-  Constant? getSeenUnnamedEnumConstant(String usr) =>
+  void addUnnamedEnumConstantToSeen(
+    String usr,
+    UnnamedEnumConstant enumConstant,
+  ) => _unnamedEnumConstants[usr] = enumConstant;
+  UnnamedEnumConstant? getSeenUnnamedEnumConstant(String usr) =>
       _unnamedEnumConstants[usr];
   bool isSeenGlobalVar(String usr) => _globals.containsKey(usr);
   void addGlobalVarToSeen(String usr, Global global) => _globals[usr] = global;
   Global? getSeenGlobalVar(String usr) => _globals[usr];
-  bool isSeenVariableConstant(String usr) =>
-      _variableConstants.containsKey(usr);
-  void addVariableConstantToSeen(String usr, Constant constant) =>
-      _variableConstants[usr] = constant;
-  Constant? getSeenVariableConstant(String usr) => _variableConstants[usr];
   bool isSeenTypealias(String usr) => _typealiases.containsKey(usr);
   void addTypealiasToSeen(String usr, Typealias t) => _typealiases[usr] = t;
   Typealias? getSeenTypealias(String usr) => _typealiases[usr];