- report tear offs using the x#y syntax as a compilation error

runtime/vm/parser.cc

 // Copyright (c) 2012, 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 "vm/parser.h"
 #include "vm/flags.h"
 
 #ifndef DART_PRECOMPILED_RUNTIME
 
 #include "lib/invocation_mirror.h"
@@ skipping 26 matching lines @@
 #include "vm/symbols.h"
 #include "vm/tags.h"
 #include "vm/timeline.h"
 #include "vm/timer.h"
 #include "vm/zone.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, enable_debug_break, false, "Allow use of break \"message\".");
 DEFINE_FLAG(bool, trace_parser, false, "Trace parser operations.");
-DEFINE_FLAG(bool, warn_new_tearoff_syntax, true, "Warning on new tear off.");
+DEFINE_FLAG(bool,
+            support_deprecated_tearoff_syntax,
+            false,
+            "Support new tear-off syntax.");
 // TODO(floitsch): remove the conditional-directive flag, once we publicly
 // committed to the current version.
 DEFINE_FLAG(bool,
             conditional_directives,
             true,
             "Enable conditional directives");
 DEFINE_FLAG(bool, generic_method_syntax, true, "Enable generic functions.");
 DEFINE_FLAG(bool,
             initializing_formal_access,
             true,
@@ skipping 11639 matching lines @@
       return left;
     }
     ASSERT(selector != NULL);
     left = selector;
   }
 }
 
 
 // Closurization e#m of getter, setter, method or operator.
 AstNode* Parser::ParseClosurization(AstNode* primary) {
-  if (FLAG_warn_new_tearoff_syntax) {
-    ReportWarning(
-        "Tear-offs using the x#id syntax is a deprecated feature,"
-        "it will not be supported in the next release");
+  if (!FLAG_support_deprecated_tearoff_syntax) {
+    ReportError("tear-off using the x#id syntax is a deprecated feature");
+    return NULL;
   }
   ExpectToken(Token::kHASH);
   TokenPosition property_pos = TokenPos();
   bool is_setter_name = false;
 
   String& extractor_name = String::ZoneHandle(Z);
   if (IsIdentifier()) {
     extractor_name = CurrentLiteral()->raw();
     ConsumeToken();
     if (CurrentToken() == Token::kASSIGN) {
@@ skipping 21 matching lines @@
     const bool is_private_name =
         (extractor_name.CharAt(0) == Library::kPrivateIdentifierStart);
     if (!is_private_name) {
       // Private names are not exported by libraries. The name mangling
       // of private names with a library-specific suffix usually ensures
       // that _x in library A is not found when looked up from library B.
       // In the pathological case where a library imports itself with
       // a prefix, the name mangling does not help in hiding the private
       // name, so we explicitly prevent lookup of private names here.
       if (is_setter_name) {
-        String& setter_name =
+        const String& setter_name =
             String::Handle(Z, Field::SetterName(extractor_name));
         obj = prefix.LookupObject(setter_name);
       }
       if (obj.IsNull()) {
         obj = prefix.LookupObject(extractor_name);
       }
     }
     if (!prefix.is_loaded() && (parsed_function() != NULL) &&
         !FLAG_load_deferred_eagerly) {
       // Remember that this function depends on an import prefix of an
       // unloaded deferred library.
       parsed_function()->AddDeferredPrefix(prefix);
     }
 
     if (obj.IsFunction()) {
       const Function& func = Function::Cast(obj);
       if (!func.IsSetterFunction() || is_setter_name) {
         return CreateImplicitClosureNode(func, property_pos, NULL);
       }
     } else if (obj.IsField()) {
       const Field& field = Field::Cast(obj);
       if (is_setter_name && !field.is_final()) {
-        Instance& setter_closure = Instance::ZoneHandle(field.SetterClosure());
+        const Instance& setter_closure =
+            Instance::ZoneHandle(field.SetterClosure());
         return new (Z) LiteralNode(property_pos, setter_closure);
       }
       if (!is_setter_name) {
-        Instance& getter_closure = Instance::ZoneHandle(field.GetterClosure());
+        const Instance& getter_closure =
+            Instance::ZoneHandle(field.GetterClosure());
         return new (Z) LiteralNode(property_pos, getter_closure);
       }
     }
     return ThrowNoSuchMethodError(
         property_pos, current_class(), extractor_name,
         NULL,  // No arguments.
         InvocationMirror::kTopLevel,
         is_setter_name ? InvocationMirror::kSetter : InvocationMirror::kMethod,
         NULL);  // No existing function.
   }
@@ skipping 1551 matching lines @@
       (la3 == Token::kLT) || (la3 == Token::kPERIOD) || (la3 == Token::kHASH);
   LibraryPrefix& prefix = LibraryPrefix::ZoneHandle(Z);
   AbstractType& type =
       AbstractType::Handle(Z, ParseType(ClassFinalizer::kCanonicalizeWellFormed,
                                         true,  // allow deferred type
                                         consume_unresolved_prefix, &prefix));
   // A constructor tear-off closure can only have been created for a
   // type that is loaded.
   ASSERT(prefix.IsNull() || prefix.is_loaded());
   ASSERT(!type.IsMalformed() && !type.IsTypeParameter());
-  if (FLAG_warn_new_tearoff_syntax) {
-    ReportWarning(
-        "Tear-offs using the x#id syntax is a deprecated feature,"
-        "it will not be supported in the next release");
+  if (!FLAG_support_deprecated_tearoff_syntax) {
+    ReportError("tear-off using the x#id syntax is a deprecated feature");
+    return;
   }
   ExpectToken(Token::kHASH);
   String* named_constructor = NULL;
   if (IsIdentifier()) {
     named_constructor = CurrentLiteral();
     ConsumeToken();
   }
   // Resolve the type and optional identifier to a constructor or factory.
   Class& type_class = Class::Handle(Z, type.type_class());
   String& type_class_name = String::Handle(Z, type_class.Name());
@@ skipping 76 matching lines @@
                 String::Handle(Z, type_class.Name()).ToCString());
   }
 
   // The type can be followed by an optional named constructor identifier.
   // Note that we tell ParseType() above not to consume it as part of
   // a misinterpreted qualified identifier. Only a valid library
   // prefix is accepted as qualifier.
   String* named_constructor = NULL;
   const bool is_tearoff_expression = (CurrentToken() == Token::kHASH);
   if (is_tearoff_expression) {
+    if (!FLAG_support_deprecated_tearoff_syntax) {
+      ReportError("tear-off using the x#id syntax is a deprecated feature");
+    }
     if (is_const) {
       ReportError("tear-off closure not allowed with const allocation");
     }
-    if (FLAG_warn_new_tearoff_syntax) {
-      ReportWarning(
-          "Tear-offs using the x#id syntax is a deprecated feature,"
-          "and will not be supported in the next release");
-    }
     ConsumeToken();
     if (IsIdentifier()) {
       named_constructor = ExpectIdentifier("name of constructor expected");
     }
   } else if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();
     named_constructor = ExpectIdentifier("name of constructor expected");
   }
 
   // Parse constructor parameters.
@@ skipping 417 matching lines @@
   ASSERT(!is_top_level_);
   AstNode* primary = NULL;
   const Token::Kind token = CurrentToken();
   if (IsFunctionLiteral()) {
     primary = ParseFunctionStatement(true);
   } else if (IsIdentifier()) {
     TokenPosition qual_ident_pos = TokenPos();
     const LibraryPrefix& prefix = LibraryPrefix::ZoneHandle(Z, ParsePrefix());
     if (!prefix.IsNull()) {
       if (CurrentToken() == Token::kHASH) {
-        if (FLAG_warn_new_tearoff_syntax) {
-          ReportWarning(
-              "Tear-offs using the x#id syntax is a deprecated feature,"
-              "it will not be supported in the next release");
+        if (!FLAG_support_deprecated_tearoff_syntax) {
+          ReportError("tear-off using the x#id syntax is a deprecated feature");
         }
         // Closurization of top-level entity in prefix scope.
         return new (Z) LiteralNode(qual_ident_pos, prefix);
       } else {
         ExpectToken(Token::kPERIOD);
       }
     }
     String& ident = *CurrentLiteral();
     ConsumeToken();
     if (prefix.IsNull()) {
@@ skipping 684 matching lines @@
     const ArgumentListNode& function_args,
     const LocalVariable* temp_for_last_arg,
     bool is_super_invocation) {
   UNREACHABLE();
   return NULL;
 }
 
 }  // namespace dart
 
 #endif  // DART_PRECOMPILED_RUNTIME