Make Script::GetTokenLocation() and Script::TokenRangeAtLine() use token streams where possible.

runtime/vm/object_test.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/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
@@ skipping 2046 matching lines @@
   const Script& script = Script::Handle(
       Script::New(url, source, RawScript::kScriptTag));
   script.SetLocationOffset(line_offset, col_offset);
 
   String& str = String::Handle();
   str = script.GetLine(first_dart_line);
   EXPECT_STREQ("main() {", str.ToCString());
   str = script.GetLine(last_dart_line);
   EXPECT_STREQ("  }", str.ToCString());
 
+  script.Tokenize(String::Handle(String::New("ABC")));
+  // Tokens: 0: kIDENT, 1: kLPAREN, 2: kRPAREN, 3: kLBRACE, 4: kNEWLINE,
+  //         5: kRETURN, 6: kSTRING, 7: kSEMICOLON, 8: kNEWLINE,
+  //         9: kRBRACE, 10: kNEWLINE
 
-  script.Tokenize(String::Handle(String::New("ABC")));
   intptr_t line, col;
+  intptr_t fast_line;
   script.GetTokenLocation(0, &line, &col);
   EXPECT_EQ(first_dart_line, line);
   EXPECT_EQ(col, col_offset + 1);
 
-  script.GetTokenLocation(4, &line, &col);  // Token 'return'
+  // We allow asking for only the line number, which only scans the token stream
+  // instead of rescanning the script.
+  script.GetTokenLocation(0, &fast_line, NULL);
+  EXPECT_EQ(line, fast_line);
+
+  script.GetTokenLocation(5, &line, &col);  // Token 'return'
   EXPECT_EQ(4, line);  // 'return' is in line 4.
   EXPECT_EQ(5, col);   // Four spaces before 'return'.
 
+  // We allow asking for only the line number, which only scans the token stream
+  // instead of rescanning the script.
+  script.GetTokenLocation(5, &fast_line, NULL);
+  EXPECT_EQ(line, fast_line);
+
   intptr_t first_idx, last_idx;
   script.TokenRangeAtLine(3, &first_idx, &last_idx);
   EXPECT_EQ(0, first_idx);  // Token 'main' is first token.
   EXPECT_EQ(3, last_idx);   // Token { is last token.
+  script.TokenRangeAtLine(4, &first_idx, &last_idx);
+  EXPECT_EQ(5, first_idx);  // Token 'return' is first token.
+  EXPECT_EQ(7, last_idx);   // Token ; is last token.
   script.TokenRangeAtLine(5, &first_idx, &last_idx);
   EXPECT_EQ(9, first_idx);  // Token } is first and only token.
   EXPECT_EQ(9, last_idx);
+  script.TokenRangeAtLine(1, &first_idx, &last_idx);
+  EXPECT_EQ(0, first_idx);
+  EXPECT_EQ(3, last_idx);
+  script.TokenRangeAtLine(6, &first_idx, &last_idx);
+  EXPECT_EQ(-1, first_idx);
+  EXPECT_EQ(-1, last_idx);
+  script.TokenRangeAtLine(1000, &first_idx, &last_idx);
+  EXPECT_EQ(-1, first_idx);
+  EXPECT_EQ(-1, last_idx);
 }
 
 
 TEST_CASE(Context) {
   const int kNumVariables = 5;
   const Context& parent_context = Context::Handle(Context::New(0));
   EXPECT_EQ(parent_context.isolate(), Isolate::Current());
   const Context& context = Context::Handle(Context::New(kNumVariables));
   context.set_parent(parent_context);
   const Context& check_parent_context = Context::Handle(context.parent());
@@ skipping 1355 matching lines @@
   cls = Object::dynamic_class();
   array = cls.fields();
   EXPECT(!array.IsNull());
   EXPECT(array.IsArray());
   array = cls.functions();
   EXPECT(!array.IsNull());
   EXPECT(array.IsArray());
 }
 
 }  // namespace dart