Fix Function.end_token_pos() and implement MethodMirror.source getter

runtime/lib/mirrors.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 "lib/invocation_mirror.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
@@ skipping 1274 matching lines @@
 
 DEFINE_NATIVE_ENTRY(MethodMirror_return_type, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   // We handle constructors in Dart code.
   ASSERT(!func.IsConstructor());
   return func.result_type();
 }
 
 
+DEFINE_NATIVE_ENTRY(MethodMirror_source, 1) {
+  GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
+  const Function& func = Function::Handle(ref.GetFunctionReferent());
+  const Script& script = Script::Handle(func.script());
+  const TokenStream& stream = TokenStream::Handle(script.tokens());
+  const TokenStream::Iterator tkit(stream, func.end_token_pos());
+  intptr_t from_line;
+  intptr_t from_col;
+  intptr_t to_line;
+  intptr_t to_col;
+  script.GetTokenLocation(func.token_pos(), &from_line, &from_col);
+  script.GetTokenLocation(func.end_token_pos(), &to_line, &to_col);
+  intptr_t last_tok_len = String::Handle(tkit.CurrentLiteral()).Length();
+  // Handle special cases for end tokens of closures (where we exclude the last
+  // token):
+  // (1) "foo(() => null, bar);": End token is `,', but we don't print it.
+  // (2) "foo(() => null);": End token is ')`, but we don't print it.
+  // (3) "var foo = () => null;": End token is `;', but in this case the token
+  // semicolon belongs to the assignment so we skip it.
+  if ((tkit.CurrentTokenKind() == Token::kCOMMA) ||                   // Case 1.
+      (tkit.CurrentTokenKind() == Token::kRPAREN) ||                  // Case 2.
+      (tkit.CurrentTokenKind() == Token::kSEMICOLON &&
+       String::Handle(func.name()).Equals("<anonymous closure>"))) {  // Case 3.
+    last_tok_len = 0;
+  }
+  return script.GetSnippet(from_line, from_col, to_line, to_col + last_tok_len);
+}
+
+
 DEFINE_NATIVE_ENTRY(TypedefMirror_referent, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Class& cls = Class::Handle(ref.GetClassReferent());
   const Function& sig_func = Function::Handle(cls.signature_function());
   const Class& sig_cls = Class::Handle(sig_func.signature_class());
   return MirrorReference::New(sig_cls);
 }
 
 
 DEFINE_NATIVE_ENTRY(ParameterMirror_type, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, pos, arguments->NativeArgAt(1));
   const Function& func = Function::Handle(ref.GetFunctionReferent());
   return func.ParameterTypeAt(func.NumImplicitParameters() + pos.Value());
 }
 
 
 DEFINE_NATIVE_ENTRY(VariableMirror_type, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Field& field = Field::Handle(ref.GetFieldReferent());
   return field.type();
 }
 
 }  // namespace dart