Added support for Global variables (#139) (#165)

CHANGELOG.md

@@ -1,3 +1,6 @@
+# 2.0.0-dev.4
+- Add support for parsing and generating globals.
+
 # 2.0.0-dev.3
 - Removed the usage of `--no-sound-null-safety` flag.
 

README.md

@@ -144,7 +144,7 @@ compiler-opts: '-I/usr/lib/llvm-9/include/'
   </td>
   </tr>
   <tr>
-    <td>functions<br>structs<br>enums<br>unnamed-enums<br>macros</td>
+    <td>functions<br>structs<br>enums<br>unnamed-enums<br>macros<br>globals</td>
     <td>Filters for declarations.<br><b>Default: all are included</b></td>
     <td>
 
@@ -170,6 +170,12 @@ enums:
     'CXTypeKind': # Full names have higher priority.
       # $1 keeps only the 1st group i.e '(.*)'.
       'CXType(.*)': '$1'
+globals:
+  exclude:
+    - aGlobal
+  rename:
+    # Removes '_' from beginning of a name.
+    - '_(.*)': '$1'
 ```
   </td>
   </tr>

lib/src/code_generator/global.dart

@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:ffigen/src/code_generator/typedef.dart';
+
 import 'binding.dart';
 import 'binding_string.dart';
 import 'type.dart';
@@ -34,20 +36,40 @@ class Global extends LookUpBinding {
           dartDoc: dartDoc,
         );
 
+  List<Typedef>? _typedefDependencies;
+  @override
+  List<Typedef> getTypedefDependencies(Writer w) {
+    if (_typedefDependencies == null) {
+      _typedefDependencies = <Typedef>[];
+
+      // Add typedef's required by the variable's type.
+      final valueType = type.getBaseType();
+      if (valueType.broadType == BroadType.NativeFunction) {
+        _typedefDependencies!.addAll(valueType.nativeFunc!.getDependencies());
+      }
+    }
+    return _typedefDependencies!;
+  }
+
   @override
   BindingString toBindingString(Writer w) {
     final s = StringBuffer();
     final globalVarName = name;
     if (dartDoc != null) {
       s.write(makeDartDoc(dartDoc!));
     }
+    final pointerName = w.wrapperLevelUniqueNamer.makeUnique('_$globalVarName');
+    final dartType = type.getDartType(w);
+    final cType = type.getCType(w);
+    final refOrValue = type.broadType == BroadType.Struct ? 'ref' : 'value';
 
-    final holderVarName =
-        w.wrapperLevelUniqueNamer.makeUnique('_$globalVarName');
     s.write(
-        '${w.ffiLibraryPrefix}.Pointer<${type.getCType(w)}> $holderVarName;\n');
-    s.write(
-        "${type.getDartType(w)} get $globalVarName => ($holderVarName ??= ${w.dylibIdentifier}.lookup<${type.getCType(w)}>('$originalName')).value;\n\n");
+        "late final ${w.ffiLibraryPrefix}.Pointer<$dartType> $pointerName = ${w.dylibIdentifier}.lookup<$cType>('$originalName');\n\n");
+    s.write('$dartType get $globalVarName => $pointerName.$refOrValue;\n\n');
+    if (type.broadType != BroadType.Struct) {
+      s.write(
+          'set $globalVarName($dartType value) => $pointerName.value = value;\n\n');
+    }
 
     return BindingString(type: BindingStringType.global, string: s.toString());
   }

lib/src/config_provider/config.dart

@@ -51,6 +51,10 @@ class Config {
   Declaration get unnamedEnumConstants => _unnamedEnumConstants;
   late Declaration _unnamedEnumConstants;
 
+  /// Declaration config for Globals.
+  Declaration get globals => _globals;
+  late Declaration _globals;
+
   /// Declaration config for Macro constants.
   Declaration get macroDecl => _macroDecl;
   late Declaration _macroDecl;
@@ -222,6 +226,15 @@ class Config {
         extractedResult: (dynamic result) =>
             _unnamedEnumConstants = result as Declaration,
       ),
+      strings.globals: Specification<Declaration>(
+        requirement: Requirement.no,
+        validator: declarationConfigValidator,
+        extractor: declarationConfigExtractor,
+        defaultValue: () => Declaration(),
+        extractedResult: (dynamic result) {
+          _globals = result as Declaration;
+        },
+      ),
       strings.macros: Specification<Declaration>(
         requirement: Requirement.no,
         validator: declarationConfigValidator,

lib/src/header_parser/includer.dart

@@ -47,6 +47,16 @@ bool shouldIncludeUnnamedEnumConstant(String usr, String name) {
   }
 }
 
+bool shouldIncludeGlobalVar(String usr, String name) {
+  if (bindingsIndex.isSeenGlobalVar(usr) || name == '') {
+    return false;
+  } else if (config.globals.shouldInclude(name)) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
 bool shouldIncludeMacro(String usr, String name) {
   if (bindingsIndex.isSeenMacro(usr) || name == '') {
     return false;

lib/src/header_parser/sub_parsers/var_parser.dart

@@ -0,0 +1,47 @@
+// Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:ffigen/src/code_generator.dart';
+import 'package:ffigen/src/header_parser/data.dart';
+import 'package:ffigen/src/header_parser/includer.dart';
+import 'package:logging/logging.dart';
+
+import '../clang_bindings/clang_bindings.dart' as clang_types;
+import '../data.dart';
+import '../utils.dart';
+
+final _logger = Logger('ffigen.header_parser.var_parser');
+
+/// Parses a global variable
+Global? parseVarDeclaration(clang_types.CXCursor cursor) {
+  final name = cursor.spelling();
+  final usr = cursor.usr();
+  if (bindingsIndex.isSeenGlobalVar(usr)) {
+    return bindingsIndex.getSeenGlobalVar(usr);
+  }
+  if (!shouldIncludeGlobalVar(usr, name)) {
+    return null;
+  }
+
+  _logger.fine('++++ Adding Global: ${cursor.completeStringRepr()}');
+
+  final type = cursor.type().toCodeGenType();
+  if (type.getBaseType().broadType == BroadType.Unimplemented ||
+      type.getBaseType().isIncompleteStruct) {
+    _logger.fine(
+        '---- Removed Global, reason: unsupported type: ${cursor.completeStringRepr()}');
+    _logger.warning("Skipped global variable '$name', type not supported.");
+    return null;
+  }
+
+  final global = Global(
+    originalName: name,
+    name: config.globals.renameUsingConfig(name),
+    usr: usr,
+    type: type,
+    dartDoc: getCursorDocComment(cursor),
+  );
+  bindingsIndex.addGlobalVarToSeen(usr, global);
+  return global;
+}

lib/src/header_parser/translation_unit_parser.dart

@@ -6,6 +6,7 @@ import 'dart:ffi';
 
 import 'package:ffigen/src/code_generator.dart';
 import 'package:ffigen/src/header_parser/sub_parsers/macro_parser.dart';
+import 'package:ffigen/src/header_parser/sub_parsers/var_parser.dart';
 import 'package:logging/logging.dart';
 
 import 'clang_bindings/clang_bindings.dart' as clang_types;
@@ -58,6 +59,9 @@ int _rootCursorVisitor(clang_types.CXCursor cursor, clang_types.CXCursor parent,
         case clang_types.CXCursorKind.CXCursor_MacroDefinition:
           saveMacroDefinition(cursor);
           break;
+        case clang_types.CXCursorKind.CXCursor_VarDecl:
+          addToBindings(parseVarDeclaration(cursor));
+          break;
         default:
           _logger.finer('rootCursorVisitor: CursorKind not implemented');
       }

lib/src/header_parser/utils.dart

@@ -316,6 +316,7 @@ class BindingsIndex {
   final Map<String, EnumClass> _enumClass = {};
   final Map<String, Constant> _unnamedEnumConstants = {};
   final Map<String, String> _macros = {};
+  final Map<String, Global> _globals = {};
   // Stores only named typedefC used in NativeFunc.
   final Map<String, Typedef> _functionTypedefs = {};
 
@@ -367,6 +368,18 @@ class BindingsIndex {
     return _unnamedEnumConstants[usr];
   }
 
+  bool isSeenGlobalVar(String usr) {
+    return _globals.containsKey(usr);
+  }
+
+  void addGlobalVarToSeen(String usr, Global global) {
+    _globals[usr] = global;
+  }
+
+  Global? getSeenGlobalVar(String usr) {
+    return _globals[usr];
+  }
+
   bool isSeenMacro(String usr) {
     return _macros.containsKey(usr);
   }

lib/src/strings.dart

@@ -39,6 +39,7 @@ const functions = 'functions';
 const structs = 'structs';
 const enums = 'enums';
 const unnamedEnums = 'unnamed-enums';
+const globals = 'globals';
 const macros = 'macros';
 
 // Sub-fields of Declarations.

pubspec.yaml

@@ -3,7 +3,7 @@
 # BSD-style license that can be found in the LICENSE file.
 
 name: ffigen
-version: 2.0.0-dev.3
+version: 2.0.0-dev.4
 homepage: https://github.com/dart-lang/ffigen
 description: Experimental generator for FFI bindings, using LibClang to parse C header files.
 

test/code_generator_test.dart

@@ -436,14 +436,23 @@ final ffi.DynamicLibrary _dylib;
 /// The symbols are looked up in [dynamicLibrary].
 Bindings(ffi.DynamicLibrary dynamicLibrary): _dylib = dynamicLibrary;
 
-ffi.Pointer<ffi.Int32> _test1;
-int get test1 => (_test1 ??= _dylib.lookup<ffi.Int32>('test1')).value;
+late final ffi.Pointer<int> _test1 = _dylib.lookup<ffi.Int32>('test1');
 
-ffi.Pointer<ffi.Pointer<ffi.Float>> _test2;
-ffi.Pointer<ffi.Float> get test2 => (_test2 ??= _dylib.lookup<ffi.Pointer<ffi.Float>>('test2')).value;
+int get test1 => _test1.value;
 
-ffi.Pointer<ffi.Pointer<Some>> _test5;
-ffi.Pointer<Some> get test5 => (_test5 ??= _dylib.lookup<ffi.Pointer<Some>>('test5')).value;
+set test1(int value) => _test1.value = value;
+
+late final ffi.Pointer<ffi.Pointer<ffi.Float>> _test2 = _dylib.lookup<ffi.Pointer<ffi.Float>>('test2');
+
+ffi.Pointer<ffi.Float> get test2 => _test2.value;
+
+set test2(ffi.Pointer<ffi.Float> value) => _test2.value = value;
+
+late final ffi.Pointer<ffi.Pointer<Some>> _test5 = _dylib.lookup<ffi.Pointer<Some>>('test5');
+
+ffi.Pointer<Some> get test5 => _test5.value;
+
+set test5(ffi.Pointer<Some> value) => _test5.value = value;
 
 }
 

test/header_parser_tests/globals.h

@@ -0,0 +1,15 @@
+// Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include <stdint.h>
+#include <stdbool.h>
+
+bool coolGlobal;
+int32_t myInt;
+int32_t *aGlobalPointer;
+long double longDouble;
+long double *pointerToLongDouble;
+
+// This should be ignored
+int GlobalIgnore;

test/header_parser_tests/globals_test.dart

@@ -0,0 +1,75 @@
+// Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:ffigen/src/code_generator.dart';
+import 'package:ffigen/src/header_parser.dart' as parser;
+import 'package:ffigen/src/config_provider.dart';
+import 'package:test/test.dart';
+import 'package:yaml/yaml.dart' as yaml;
+import 'package:ffigen/src/strings.dart' as strings;
+
+import '../test_utils.dart';
+
+late Library actual, expected;
+
+void main() {
+  group('globals_test', () {
+    setUpAll(() {
+      logWarnings();
+      expected = expectedLibrary();
+      actual = parser.parse(
+        Config.fromYaml(yaml.loadYaml('''
+${strings.name}: 'NativeLibrary'
+${strings.description}: 'Globals Test'
+${strings.output}: 'unused'
+${strings.headers}:
+  ${strings.entryPoints}:
+    - 'test/header_parser_tests/globals.h'
+  ${strings.includeDirectives}:
+    - '**globals.h'
+${strings.globals}:
+  ${strings.exclude}:
+    - GlobalIgnore
+# Needed for stdbool.h in MacOS
+${strings.compilerOpts}: '-I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Kernel.framework/Headers/ -Wno-nullability-completeness'
+        ''') as yaml.YamlMap),
+      );
+    });
+
+    test('Total bindings count', () {
+      expect(actual.bindings.length, expected.bindings.length);
+    });
+
+    test('Parse global Values', () {
+      expect(actual.getBindingAsString('coolGlobal'),
+          expected.getBindingAsString('coolGlobal'));
+      expect(actual.getBindingAsString('myInt'),
+          expected.getBindingAsString('myInt'));
+      expect(actual.getBindingAsString('aGlobalPointer'),
+          expected.getBindingAsString('aGlobalPointer'));
+    });
+
+    test('Ignore global values', () {
+      expect(() => actual.getBindingAsString('GlobalIgnore'),
+          throwsA(TypeMatcher<NotFoundException>()));
+      expect(() => actual.getBindingAsString('longDouble'),
+          throwsA(TypeMatcher<NotFoundException>()));
+      expect(() => actual.getBindingAsString('pointerToLongDouble'),
+          throwsA(TypeMatcher<NotFoundException>()));
+    });
+  });
+}
+
+Library expectedLibrary() {
+  return Library(
+    name: 'Bindings',
+    bindings: [
+      Global(type: Type.boolean(), name: 'coolGlobal'),
+      Global(type: Type.nativeType(SupportedNativeType.Int32), name: 'myInt'),
+      Global(
+          type: Type.pointer(Type.nativeType(SupportedNativeType.Int32)),
+          name: 'aGlobalPointer'),
+    ],
+  );
+}