Preserve type variables in closure conversion.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/become.h"
@@ skipping 6860 matching lines @@
 //     return (#contextParameter[1]).+(
 //       let final dynamic #t1 = #contextParameter[2] in
 //         let final dynamic #t2 = #contextParameter[2] = #t1.+(1) in
 //           #t1
 //     );
 //   }
 //
 // Converted closure functions are used in VM Closure instances that represent
 // the results of evaluation of [MakeClosure] primitive operations.
 //
-// Internally, converted closure functins are represented with the same Closure
+// Internally, converted closure functions are represented with the same Closure
 // class as implicit closure functions (that are used for dealing with
 // tear-offs).  The Closure class instances have two fields, one for the
 // function, and one for the captured context.  Implicit closure functions have
 // pre-defined shape of the context: it's a single variable that is used as
 // 'this'.  Converted closure functions use the context field to store the
 // vector of captured variables that will be supplied as the first argument
 // during invocation.
 //
 // The top-level functions used in converted closure functions are generated
 // during a front-end transformation in Kernel.  Those functions have some
 // common properties:
 //   * they expect the captured context to be passed as the first argument,
 //   * the first argument should be of [Vector] type (index-based storage),
 //   * they retrieve the captured variables from [Vector] explicitly, so they
 //   don't need the variables from the context to be put into their current
 //   scope.
 //
 // During closure-conversion pass in Kernel, the contexts are generated
 // explicitly and are represented as [Vector]s.  Then they are paired together
 // with the top-level functions to form a closure.  When the closure, created
 // this way, is invoked, it should receive the [Vector] as the first argument,
 // and take the rest of the arguments from the invocation.
 //
-// Converted cosure functions in VM follow same discipline as implicit closure
+// Converted closure functions in VM follow same discipline as implicit closure
 // functions, because they are similar in many ways. For further deatils, please
 // refer to the following methods:
 //   -> Function::ConvertedClosureFunction
 //   -> StreamingFlowGraphBuilder::BuildGraphOfConvertedClosureFunction
 //   -> StreamingFlowGraphBuilder::BuildGraph (small change that calls
 //      BuildGraphOfConvertedClosureFunction)
 //   -> StreamingFlowGraphBuilder::BuildClosureCreation (converted closure
 //      functions are created here)
 //
 // Function::ConvertedClosureFunction method follows the logic of
@@ skipping 15608 matching lines @@
   }
   return UserTag::null();
 }
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart