Switch "length" custom prop of Node to a class field. This saves a ba…

…sic object when for every node in IDE mode and makes the length available everwhere so we can improve error message and such things.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=129376537

src/com/google/javascript/jscomp/parsing/IRFactory.java

@@ -850,7 +850,7 @@ static int charno(SourcePosition location) {
   void setSourceInfo(Node node, Node ref) {
     node.setLineno(ref.getLineno());
     node.setCharno(ref.getCharno());
-    maybeSetLengthFrom(node, ref);
+    setLengthFrom(node, ref);
   }
 
   void setSourceInfo(Node irNode, ParseTree node) {
@@ -874,7 +874,7 @@ void setSourceInfo(
       node.setLineno(lineno);
       int charno = charno(start);
       node.setCharno(charno);
-      maybeSetLength(node, start, end);
+      setLength(node, start, end);
     }
   }
 
@@ -936,17 +936,13 @@ private JSDocInfo parseInlineTypeDoc(Comment node) {
   }
 
   // Set the length on the node if we're in IDE mode.
-  void maybeSetLength(
+  void setLength(
       Node node, SourcePosition start, SourcePosition end) {
-    if (config.preserveDetailedSourceInfo == Config.SourceLocationInformation.PRESERVE) {
-      node.setLength(end.offset - start.offset);
-    }
+    node.setLength(end.offset - start.offset);
   }
 
-  void maybeSetLengthFrom(Node node, Node ref) {
-    if (config.preserveDetailedSourceInfo == Config.SourceLocationInformation.PRESERVE) {
-      node.setLength(ref.getLength());
-    }
+  void setLengthFrom(Node node, Node ref) {
+    node.setLength(ref.getLength());
   }
 
   private class TransformDispatcher {
@@ -1990,7 +1986,7 @@ Node processVariableDeclaration(VariableDeclarationTree decl) {
       if (decl.initializer != null) {
         Node initializer = transform(decl.initializer);
         lhs.addChildToBack(initializer);
-        maybeSetLength(lhs, decl.location.start, decl.location.end);
+        setLength(lhs, decl.location.start, decl.location.end);
       }
       maybeProcessType(lhs, decl.declaredType);
       return lhs;

src/com/google/javascript/rhino/Node.java

@@ -89,8 +89,6 @@ public class Node implements Serializable {
       FREE_CALL          = 50,    // A CALL without an explicit "this" value.
       STATIC_SOURCE_FILE = 51,    // A StaticSourceFile indicating the file
                                   // where this node lives.
-      LENGTH             = 52,    // The length of the code represented by
-                                  // this node.
       INPUT_ID           = 53,    // The id of the input associated with this
                                   // node.
       SLASH_V            = 54,    // Whether a STRING node contains a \v
@@ -174,7 +172,6 @@ private static final String propToString(int propType) {
         case FREE_CALL:          return "free_call";
         case STATIC_SOURCE_FILE: return "source_file";
         case INPUT_ID:           return "input_id";
-        case LENGTH:             return "length";
         case SLASH_V:            return "slash_v";
         case INFERRED_FUNCTION:  return "inferred";
         case CHANGE_TIME:        return "change_time";
@@ -1254,6 +1251,9 @@ private static void toStringTreeHelper(Node n, int level, Appendable sb)
    */
   private int sourcePosition;
 
+  /** The length of the code represented by the node. */
+  private int length;
+
   private TypeI typei;
 
   protected Node parent;
@@ -1320,11 +1320,11 @@ public boolean isFromExterns() {
   }
 
   public int getLength() {
-    return getIntProp(LENGTH);
+    return this.length;
   }
 
   public void setLength(int length) {
-    putIntProp(LENGTH, length);
+    this.length = length;
   }
 
   public int getLineno() {
@@ -2157,7 +2157,7 @@ public Node useSourceInfoFrom(Node other) {
     putProp(ORIGINALNAME_PROP, other.getProp(ORIGINALNAME_PROP));
     setStaticSourceFile(other.getStaticSourceFile());
     sourcePosition = other.sourcePosition;
-    setLength(other.getLength());
+    length = other.length;
     return this;
   }
 
@@ -2194,7 +2194,7 @@ public Node useSourceInfoIfMissingFrom(Node other) {
     if (getStaticSourceFile() == null) {
       setStaticSourceFile(other.getStaticSourceFile());
       sourcePosition = other.sourcePosition;
-      setLength(other.getLength());
+      length = other.length;
     }
 
     return this;