instantiate generic tear-offs, fixes #525

[email protected]

Review URL: https://codereview.chromium.org/1930323004 .

Author: John Messerly

karma.conf.js

@@ -83,7 +83,7 @@ module.exports = function(config) {
       },
     },
 
-    browsers: ['ChromeCanary', 'Electron'],
+    browsers: ['Chrome'],
 
     // Continuous Integration mode
     // if true, Karma captures browsers, runs the tests and exits

lib/runtime/dart_sdk.js

@@ -142,6 +142,12 @@ dart_library.library('dart_sdk', null, /* Imports */[
     dart.tag(f, sig);
     return f;
   };
+  dart.gbind = function(f, ...typeArgs) {
+    let result = f(...typeArgs);
+    let sig = dart._getRuntimeType(f)(...typeArgs);
+    dart.tag(result, sig);
+    return result;
+  };
   dart._setMethodSignature = function(f, sigF) {
     dart.defineMemoizedGetter(f, dart._methodSig, () => {
       let sigObj = sigF();
@@ -462,7 +468,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
       }
     }
     if (ftype === void 0) {
-      ftype = dart.read(f);
+      ftype = dart._getRuntimeType(f);
     }
     if (!ftype) {
       if (typeArgs != null) {
@@ -490,10 +496,10 @@ dart_library.library('dart_sdk', null, /* Imports */[
     dart.throwNoSuchMethodFunc(obj, name, args, originalFunction);
   };
   dart.dcall = function(f, ...args) {
-    return dart._checkAndCall(f, dart.read(f), void 0, null, args, 'call');
+    return dart._checkAndCall(f, dart._getRuntimeType(f), void 0, null, args, 'call');
   };
   dart.dgcall = function(f, typeArgs, ...args) {
-    return dart._checkAndCall(f, dart.read(f), void 0, typeArgs, args, 'call');
+    return dart._checkAndCall(f, dart._getRuntimeType(f), void 0, typeArgs, args, 'call');
   };
   dart._callMethod = function(obj, name, typeArgs, args, displayName) {
     let symbol = dart._canonicalFieldName(obj, name, args, displayName);
@@ -758,7 +764,7 @@ dart_library.library('dart_sdk', null, /* Imports */[
     }
     return result;
   };
-  dart.read = function(value) {
+  dart._getRuntimeType = function(value) {
     return value[dart._runtimeType];
   };
   dart.tag = function(value, t) {
@@ -964,11 +970,11 @@ dart_library.library('dart_sdk', null, /* Imports */[
     return new dart.Typedef(name, closure);
   };
   dart.isDartType = function(type) {
-    return dart.read(type) === core.Type;
+    return dart._getRuntimeType(type) === core.Type;
   };
   dart.typeName = function(type) {
     if (type instanceof dart.TypeRep) return type.toString();
-    let tag = dart.read(type);
+    let tag = dart._getRuntimeType(type);
     if (tag === core.Type) {
       let name = type.name;
       let args = dart.getGenericArgs(type);

lib/src/compiler/code_generator.dart

@@ -475,7 +475,11 @@ class CodeGenerator extends GeneralizingAstVisitor
   }
 
   @override
-  JS.Expression visitTypeName(TypeName node) => _emitTypeName(node.type);
+  JS.Expression visitTypeName(TypeName node) {
+    // TODO(jmesserly): should only happen for erroneous code.
+    if (node.type == null) return js.call('dart.dynamic');
+    return _emitTypeName(node.type);
+  }
 
   @override
   JS.Statement visitClassTypeAlias(ClassTypeAlias node) {
@@ -1479,7 +1483,7 @@ class CodeGenerator extends GeneralizingAstVisitor
       for (var p in ctor.parameters.parameters) {
         var element = p.element;
         if (element is FieldFormalParameterElement) {
-          fields[element.field] = visitSimpleIdentifier(p.identifier);
+          fields[element.field] = _emitSimpleIdentifier(p.identifier);
         }
       }
 
@@ -1542,7 +1546,7 @@ class CodeGenerator extends GeneralizingAstVisitor
 
     var body = <JS.Statement>[];
     for (var param in parameters.parameters) {
-      var jsParam = visitSimpleIdentifier(param.identifier);
+      var jsParam = _emitSimpleIdentifier(param.identifier);
 
       if (!options.destructureNamedParams) {
         if (param.kind == ParameterKind.NAMED) {
@@ -1978,10 +1982,18 @@ class CodeGenerator extends GeneralizingAstVisitor
     ]);
   }
 
-  /// Writes a simple identifier. This can handle implicit `this` as well as
-  /// going through the qualified library name if necessary.
+  /// Emits a simple identifier, including handling an inferred generic
+  /// function instantiation.
   @override
   JS.Expression visitSimpleIdentifier(SimpleIdentifier node) {
+    return _applyFunctionTypeArguments(
+        _emitSimpleIdentifier(node), node.staticElement, node.staticType);
+  }
+
+  /// Emits a simple identifier, handling implicit `this` as well as
+  /// going through the qualified library name if necessary, but *not* handling
+  /// inferred generic function instantiation.
+  JS.Expression _emitSimpleIdentifier(SimpleIdentifier node) {
     var accessor = node.staticElement;
     if (accessor == null) {
       return js.commentExpression(
@@ -2334,8 +2346,8 @@ class CodeGenerator extends GeneralizingAstVisitor
     List<JS.Expression> args = _visit(node.argumentList);
     if (DynamicInvoke.get(target)) {
       if (typeArgs != null) {
-        return js.call('dart.dgsend(#, [#], #, #)',
-            [jsTarget, typeArgs, memberName, args]);
+        return js.call('dart.dgsend(#, #, #, #)',
+            [jsTarget, new JS.ArrayInitializer(typeArgs), memberName, args]);
       } else {
         return js.call('dart.dsend(#, #, #)', [jsTarget, memberName, args]);
       }
@@ -2367,7 +2379,8 @@ class CodeGenerator extends GeneralizingAstVisitor
     if (DynamicInvoke.get(node.function)) {
       var typeArgs = _emitInvokeTypeArguments(node);
       if (typeArgs != null) {
-        return js.call('dart.dgcall(#, [#], #)', [fn, typeArgs, args]);
+        return js.call('dart.dgcall(#, #, #)',
+            [fn, new JS.ArrayInitializer(typeArgs), args]);
       } else {
         return js.call('dart.dcall(#, #)', [fn, args]);
       }
@@ -2385,19 +2398,26 @@ class CodeGenerator extends GeneralizingAstVisitor
 
   List<JS.Expression> _emitInvokeTypeArguments(InvocationExpression node) {
     return _emitFunctionTypeArguments(
-        node.function.staticType, node.staticInvokeType);
+        node.function.staticType, node.staticInvokeType, node.typeArguments);
   }
 
   /// If `g` is a generic function type, and `f` is an instantiation of it,
   /// then this will return the type arguments to apply, otherwise null.
-  List<JS.Expression> _emitFunctionTypeArguments(DartType g, DartType f) {
+  List<JS.Expression> _emitFunctionTypeArguments(DartType g, DartType f,
+      [TypeArgumentList typeArgs]) {
     if (g is FunctionType &&
         g.typeFormals.isNotEmpty &&
         f is FunctionType &&
         f.typeFormals.isEmpty) {
       return _recoverTypeArguments(g, f)
           .map(_emitTypeName)
           .toList(growable: false);
+    } else if (typeArgs != null) {
+      // Dynamic calls may have type arguments, even though the function types
+      // are not known.
+      // TODO(jmesserly): seems to be mostly broken in Analyzer at the moment:
+      // https://github.com/dart-lang/sdk/issues/26368
+      return typeArgs.arguments.map(visitTypeName).toList(growable: false);
     }
     return null;
   }
@@ -3365,7 +3385,7 @@ class CodeGenerator extends GeneralizingAstVisitor
     if (isLibraryPrefix(node.prefix)) {
       return _visit(node.identifier);
     } else {
-      return _emitAccess(node.prefix, node.identifier);
+      return _emitAccess(node.prefix, node.identifier, node.staticType);
     }
   }
 
@@ -3374,7 +3394,7 @@ class CodeGenerator extends GeneralizingAstVisitor
     if (node.operator.lexeme == '?.') {
       return _emitNullSafe(node);
     }
-    return _emitAccess(_getTarget(node), node.propertyName);
+    return _emitAccess(_getTarget(node), node.propertyName, node.staticType);
   }
 
   JS.Expression _emitNullSafe(Expression node) {
@@ -3451,8 +3471,9 @@ class CodeGenerator extends GeneralizingAstVisitor
   }
 
   /// Shared code for [PrefixedIdentifier] and [PropertyAccess].
-  JS.Expression _emitAccess(Expression target, SimpleIdentifier memberId) {
-    var member = memberId.staticElement;
+  JS.Expression _emitAccess(
+      Expression target, SimpleIdentifier memberId, DartType resultType) {
+    Element member = memberId.staticElement;
     if (member is PropertyAccessorElement) {
       member = (member as PropertyAccessorElement).variable;
     }
@@ -3463,30 +3484,49 @@ class CodeGenerator extends GeneralizingAstVisitor
       return js.call('dart.dload(#, #)', [_visit(target), name]);
     }
 
-    if (target is SuperExpression &&
-        member is FieldElement &&
-        !member.isSynthetic) {
+    var jsTarget = _visit(target);
+    bool isSuper = jsTarget is JS.Super;
+
+    if (isSuper && member is FieldElement && !member.isSynthetic) {
       // If super.x is actually a field, then x is an instance property since
       // subclasses cannot override x.
-      return js.call('this.#', [name]);
+      jsTarget = new JS.This();
     }
 
-    String code;
+    JS.Expression result;
     if (member != null && member is MethodElement && !isStatic) {
       // Tear-off methods: explicitly bind it.
-      if (target is SuperExpression) {
-        return js.call('dart.bind(this, #, #.#)', [name, _visit(target), name]);
+      if (isSuper) {
+        result = js.call('dart.bind(this, #, #.#)', [name, jsTarget, name]);
       } else if (_isObjectMemberCall(target, memberId.name)) {
-        return js.call('dart.bind(#, #, dart.#)', [_visit(target), name, name]);
+        result = js.call('dart.bind(#, #, dart.#)', [jsTarget, name, name]);
+      } else {
+        result = js.call('dart.bind(#, #)', [jsTarget, name]);
       }
-      code = 'dart.bind(#, #)';
     } else if (_isObjectMemberCall(target, memberId.name)) {
-      return js.call('dart.#(#)', [name, _visit(target)]);
+      result = js.call('dart.#(#)', [name, jsTarget]);
     } else {
-      code = '#.#';
+      result = js.call('#.#', [jsTarget, name]);
+    }
+    return _applyFunctionTypeArguments(result, member, resultType);
+  }
+
+  /// If this is an inferred instantiation of a generic function/method, this
+  /// will add the inferred type arguments.
+  JS.Expression _applyFunctionTypeArguments(
+      JS.Expression result, Element member, DartType instantiated) {
+    DartType type;
+    if (member is ExecutableElement) {
+      type = member.type;
+    } else if (member is VariableElement) {
+      type = member.type;
     }
 
-    return js.call(code, [_visit(target), name]);
+    // TODO(jmesserly): handle explicitly passed type args.
+    if (type == null) return result;
+    var typeArgs = _emitFunctionTypeArguments(type, instantiated);
+    if (typeArgs == null) return result;
+    return js.call('dart.gbind(#, #)', [result, typeArgs]);
   }
 
   /// Emits a generic send, like an operator method.

test/codegen/language/generic_tearoff_test.dart

@@ -0,0 +1,44 @@
+// Copyright (c) 2016, 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 'dart:math' as math;
+import 'dart:math' show min; // <-- generic: <T extends num>(T, T) -> T
+import 'package:expect/expect.dart';
+
+class C {
+  /*=T*/ m/*<T extends num>*/(/*=T*/ x, /*=T*/ y) => min(x, y);
+  int m2(int x, int y) => min(x, y);
+}
+
+typedef int Int2Int2Int(int x, int y);
+
+void _test(Int2Int2Int f) {
+  int y = f(123, 456);
+  Expect.equals(y, 123);
+  // `f` doesn't take type args.
+  Expect.throws(() => (f as dynamic)/*<int>*/(123, 456)); 
+}
+
+void _testParam(/*=T*/ minFn/*<T extends num>*/(/*=T*/ x, /*=T*/ y)) {
+  _test(minFn);
+}
+
+main() {
+  // Strong mode infers: `min<int>`
+  // Test simple/prefixed identifiers and property access
+  _test(min); 
+  _test(math.min);
+  _test(new C().m);
+
+  // Test local function, variable, and parameter
+  /*=T*/ m/*<T extends num>*/(/*=T*/ x, /*=T*/ y) => min(x, y);
+  _test(m);
+  final f = min;
+  _test(f);
+  _testParam(math.min);
+
+  // A few misc tests for methods
+  Expect.equals(123, (new C() as dynamic).m/*<int>*/(123, 456));
+  Expect.throws(() => (new C() as dynamic).m2/*<int>*/(123, 456));
+}

tool/input_sdk/private/ddc_runtime/classes.dart

@@ -170,6 +170,17 @@ bind(obj, name, f) => JS('', '''(() => {
   return $f;
 })()''');
 
+/// Instantiate a generic method.
+///
+/// We need to apply the type arguments both to the function, as well as its
+/// associated function type.
+gbind(f, @rest typeArgs) {
+  var result = JS('', '#(...#)', f, typeArgs);
+  var sig = JS('', '#(...#)', _getRuntimeType(f), typeArgs);
+  tag(result, sig);
+  return result;
+}
+
 // Set up the method signature field on the constructor
 _setMethodSignature(f, sigF) => JS('', '''(() => {
   $defineMemoizedGetter($f, $_methodSig, () => {

tool/input_sdk/private/ddc_runtime/operations.dart

@@ -104,7 +104,7 @@ _checkAndCall(f, ftype, obj, typeArgs, args, name) => JS('', '''(() => {
   // then it should have been a function valued field, so
   // get the type from the function.
   if ($ftype === void 0) {
-    $ftype = $read($f);
+    $ftype = $_getRuntimeType($f);
   }
 
   if (!$ftype) {
@@ -150,12 +150,12 @@ _checkAndCall(f, ftype, obj, typeArgs, args, name) => JS('', '''(() => {
   $throwNoSuchMethodFunc($obj, $name, $args, originalFunction);
 })()''');
 
-dcall(f, @rest args) =>
-    _checkAndCall(f, read(f), JS('', 'void 0'), null, args, 'call');
+dcall(f, @rest args) => _checkAndCall(
+    f, _getRuntimeType(f), JS('', 'void 0'), null, args, 'call');
 
 
-dgcall(f, typeArgs, @rest args) =>
-    _checkAndCall(f, read(f), JS('', 'void 0'), typeArgs, args, 'call');
+dgcall(f, typeArgs, @rest args) => _checkAndCall(
+    f, _getRuntimeType(f), JS('', 'void 0'), typeArgs, args, 'call');
 
 
 /// Shared code for dsend, dindex, and dsetindex.

tool/input_sdk/private/ddc_runtime/rtti.dart

@@ -148,7 +148,7 @@ _nonPrimitiveRuntimeType(obj) => JS('', '''(() => {
   return result;
 })()''');
 
-read(value) => JS('', '#[#]', value, _runtimeType);
+_getRuntimeType(value) => JS('', '#[#]', value, _runtimeType);
 
 /// Tag the runtime type of [value] to be type [t].
 void tag(value, t) {

tool/input_sdk/private/ddc_runtime/types.dart

@@ -293,13 +293,13 @@ definiteFunctionType(returnType, args, extra) =>
 
 typedef(name, closure) => JS('', 'new #(#, #)', Typedef, name, closure);
 
-bool isDartType(type) => JS('bool', '#(#) === #', read, type, Type);
+bool isDartType(type) => JS('bool', '#(#) === #', _getRuntimeType, type, Type);
 
 typeName(type) => JS('', '''(() => {
   // Non-instance types
   if ($type instanceof $TypeRep) return $type.toString();
   // Instance types
-  let tag = $read($type);
+  let tag = $_getRuntimeType($type);
   if (tag === $Type) {
     let name = $type.name;
     let args = $getGenericArgs($type);