dart2js allocation tweaks

pkg/kernel/lib/ast.dart

 // 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.
 
 /// -----------------------------------------------------------------------
 ///                           ERROR HANDLING
 /// -----------------------------------------------------------------------
 ///
 /// As a rule of thumb, errors that can be detected statically are handled by
 /// the frontend, typically by translating the erroneous code into a 'throw' or
@@ skipping 4353 matching lines @@
 
   final List<int> source;
 
   String cachedText;
 
   Source(this.lineStarts, this.source);
 
   /// Return the text corresponding to [line] which is a 1-based line
   /// number. The returned line contains no line separators.
   String getTextLine(int line) {
-    _rangeCheck(line, 1, lineStarts.length, "line");
+    RangeError.checkValueInInterval(line, 1, lineStarts.length, 'line');

[ahe, 2017/05/05 05:27:44]

Did you change the error message produced by RangeError.checkValueInInterval?

[sra1, 2017/05/05 05:49:01]

No. I also think the RangeError description is confusing, but it is still
confusing with this interpolated string repeating things that are printed with
the message.

I would be supportive of an independent change to improve the corelib errors.

[ahe, 2017/05/08 10:25:21]

I'm surprised that this change was submitted although I had expressed concerns
about it and suggested ways to work around it.

     if (source == null) return null;
 
     cachedText ??= UTF8.decode(source, allowMalformed: true);
     // -1 as line numbers start at 1.
     int index = line - 1;
     if (index + 1 == lineStarts.length) {
       // Last line.
       return cachedText.substring(lineStarts[index]);
     } else if (index < lineStarts.length) {
       // We subtract 1 from the next line for two reasons:
       // 1. If the file isn't terminated by a newline, that index is invalid.
       // 2. To remove the newline at the end of the line.
       int endOfLine = lineStarts[index + 1] - 1;
       if (endOfLine > index && cachedText[endOfLine - 1] == "\r") {
         --endOfLine; // Windows line endings.
       }
       return cachedText.substring(lineStarts[index], endOfLine);
     }
     // This shouldn't happen: should have been caught by the range check above.
     throw "Internal error";
   }
 
   /// Translates an offset to line and column numbers in the given file.
   Location getLocation(String file, int offset) {
-    _rangeCheck(offset, 0, lineStarts.last, "offset");
+    RangeError.checkValueInInterval(offset, 0, lineStarts.last, 'offset');
     int low = 0, high = lineStarts.length - 1;
     while (low < high) {
       int mid = high - ((high - low) >> 1); // Get middle, rounding up.
       int pivot = lineStarts[mid];
       if (pivot <= offset) {
         low = mid;
       } else {
         high = mid - 1;
       }
     }
     int lineIndex = low;
     int lineStart = lineStarts[lineIndex];
     int lineNumber = 1 + lineIndex;
     int columnNumber = 1 + offset - lineStart;
     return new Location(file, lineNumber, columnNumber);
   }
 }
 
-void _rangeCheck(int value, int min, int max, String name) {
-  RangeError.checkValueInInterval(value, min, max, name,
-      "The value of '$name' ($value) must be between $min and $max.");
-}
-
 /// Returns the [Reference] object for the given member.
 ///
 /// Returns `null` if the member is `null`.
 Reference getMemberReference(Member member) {
   return member?.reference;
 }
 
 /// Returns the [Reference] object for the given class.
 ///
 /// Returns `null` if the class is `null`.
@@ skipping 41 matching lines @@
 /// typedef has not been assigned a canonical name yet.
 ///
 /// Returns `null` if the typedef is `null`.
 CanonicalName getCanonicalNameOfTypedef(Typedef typedef_) {
   if (typedef_ == null) return null;
   if (typedef_.canonicalName == null) {
     throw '$typedef_ has no canonical name';
   }
   return typedef_.canonicalName;
 }