[tools] Modernize tools .mjs files

This is mostly an auto-conversion done by several tools.

- use let / const
- use arrow functions
- use template strings

There are some additional manual rewrite required to modernize the
code further.

Change-Id: I63a7a43b05b14b33ad9941350d3d5f26aab10ba0
Bug: v8:10667
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2519564Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71080}

tools/arguments.mjs

@@ -27,37 +27,37 @@ export class BaseArgumentsProcessor {
           'Default log file name is "' +
           this.result_.logFileName + '".\n');
     print('Options:');
-    for (var arg in this.argsDispatch_) {
-      var synonyms = [arg];
-      var dispatch = this.argsDispatch_[arg];
-      for (var synArg in this.argsDispatch_) {
+    for (const arg in this.argsDispatch_) {
+      const synonyms = [arg];
+      const dispatch = this.argsDispatch_[arg];
+      for (const synArg in this.argsDispatch_) {
         if (arg !== synArg && dispatch === this.argsDispatch_[synArg]) {
           synonyms.push(synArg);
           delete this.argsDispatch_[synArg];
         }
       }
-      print('  ' + synonyms.join(', ').padEnd(20) + " " + dispatch[2]);
+      print(`  ${synonyms.join(', ').padEnd(20)} ${dispatch[2]}`);
     }
     quit(2);
   }
 
   parse() {
     while (this.args_.length) {
-      var arg = this.args_.shift();
+      let arg = this.args_.shift();
       if (arg.charAt(0) != '-') {
         this.result_.logFileName = arg;
         continue;
       }
-      var userValue = null;
-      var eqPos = arg.indexOf('=');
+      let userValue = null;
+      const eqPos = arg.indexOf('=');
       if (eqPos != -1) {
         userValue = arg.substr(eqPos + 1);
         arg = arg.substr(0, eqPos);
       }
       if (arg in this.argsDispatch_) {
-        var dispatch = this.argsDispatch_[arg];
-        var property = dispatch[0];
-        var defaultValue = dispatch[1];
+        const dispatch = this.argsDispatch_[arg];
+        const property = dispatch[0];
+        const defaultValue = dispatch[1];
         if (typeof defaultValue == "function") {
           userValue = defaultValue(userValue);
         } else if (userValue == null) {

tools/codemap.mjs

@@ -90,7 +90,7 @@ export class CodeMap {
    * @param {number} to The destination address.
    */
   moveCode(from, to) {
-    var removedNode = this.dynamics_.remove(from);
+    const removedNode = this.dynamics_.remove(from);
     this.deleteAllCoveredNodes_(this.dynamics_, to, to + removedNode.value.size);
     this.dynamics_.insert(to, removedNode.value);
   }
@@ -102,7 +102,7 @@ export class CodeMap {
    * @param {number} start The starting address of the entry being deleted.
    */
   deleteCode(start) {
-    var removedNode = this.dynamics_.remove(start);
+    const removedNode = this.dynamics_.remove(start);
   }
 
   /**
@@ -130,7 +130,7 @@ export class CodeMap {
    * @private
    */
   markPages_(start, end) {
-    for (var addr = start; addr <= end;
+    for (let addr = start; addr <= end;
         addr += CodeMap.PAGE_SIZE) {
       this.pages_[(addr / CodeMap.PAGE_SIZE)|0] = 1;
     }
@@ -140,16 +140,16 @@ export class CodeMap {
    * @private
    */
   deleteAllCoveredNodes_(tree, start, end) {
-    var to_delete = [];
-    var addr = end - 1;
+    const to_delete = [];
+    let addr = end - 1;
     while (addr >= start) {
-      var node = tree.findGreatestLessThan(addr);
+      const node = tree.findGreatestLessThan(addr);
       if (!node) break;
-      var start2 = node.key, end2 = start2 + node.value.size;
+      const start2 = node.key, end2 = start2 + node.value.size;
       if (start2 < end && start < end2) to_delete.push(start2);
       addr = start2 - 1;
     }
-    for (var i = 0, l = to_delete.length; i < l; ++i) tree.remove(to_delete[i]);
+    for (let i = 0, l = to_delete.length; i < l; ++i) tree.remove(to_delete[i]);
   }
 
   /**
@@ -163,7 +163,7 @@ export class CodeMap {
    * @private
    */
   findInTree_(tree, addr) {
-    var node = tree.findGreatestLessThan(addr);
+    const node = tree.findGreatestLessThan(addr);
     return node && this.isAddressBelongsTo_(addr, node) ? node : null;
   }
 
@@ -175,29 +175,29 @@ export class CodeMap {
    * @param {number} addr Address.
    */
   findAddress(addr) {
-    var pageAddr = (addr / CodeMap.PAGE_SIZE)|0;
+    const pageAddr = (addr / CodeMap.PAGE_SIZE)|0;
     if (pageAddr in this.pages_) {
       // Static code entries can contain "holes" of unnamed code.
       // In this case, the whole library is assigned to this address.
-      var result = this.findInTree_(this.statics_, addr);
+      let result = this.findInTree_(this.statics_, addr);
       if (!result) {
         result = this.findInTree_(this.libraries_, addr);
         if (!result) return null;
       }
       return { entry : result.value, offset : addr - result.key };
     }
-    var min = this.dynamics_.findMin();
-    var max = this.dynamics_.findMax();
+    const min = this.dynamics_.findMin();
+    const max = this.dynamics_.findMax();
     if (max != null && addr < (max.key + max.value.size) && addr >= min.key) {
-      var dynaEntry = this.findInTree_(this.dynamics_, addr);
+      const dynaEntry = this.findInTree_(this.dynamics_, addr);
       if (dynaEntry == null) return null;
       // Dedupe entry name.
-      var entry = dynaEntry.value;
+      const entry = dynaEntry.value;
       if (!entry.nameUpdated_) {
         entry.name = this.dynamicsNameGen_.getName(entry.name);
         entry.nameUpdated_ = true;
       }
-      return { entry : entry, offset : addr - dynaEntry.key };
+      return { entry, offset : addr - dynaEntry.key };
     }
     return null;
   }
@@ -209,7 +209,7 @@ export class CodeMap {
    * @param {number} addr Address.
    */
   findEntry(addr) {
-    var result = this.findAddress(addr);
+    const result = this.findAddress(addr);
     return result ? result.entry : null;
   }
 
@@ -219,7 +219,7 @@ export class CodeMap {
    * @param {number} addr Address.
    */
   findDynamicEntryByStartAddress(addr) {
-    var node = this.dynamics_.find(addr);
+    const node = this.dynamics_.find(addr);
     return node ? node.value : null;
   }
 
@@ -292,7 +292,7 @@ class NameGenerator {
       this.knownNames_[name] = 0;
       return name;
     }
-    var count = ++this.knownNames_[name];
+    const count = ++this.knownNames_[name];
     return name + ' {' + count + '}';
   };
 }

tools/consarray.mjs

@@ -72,7 +72,7 @@ ConsArray.prototype.atEnd = function() {
  * Returns the current item, moves to the next one.
  */
 ConsArray.prototype.next = function() {
-  var result = this.currCell_.data[this.currCellPos_++];
+  const result = this.currCell_.data[this.currCellPos_++];
   if (this.currCellPos_ >= this.currCell_.data.length) {
     this.currCell_ = this.currCell_.next;
     this.currCellPos_ = 0;

tools/csvparser.mjs

@@ -84,9 +84,9 @@ export class CsvParser {
    * @param {string} line Input line.
    */
   parseLine(line) {
-    var pos = 0;
-    var endPos = line.length;
-    var fields = [];
+    let pos = 0;
+    const endPos = line.length;
+    const fields = [];
     if (endPos == 0) return fields;
     let nextPos = 0;
     while(nextPos !== -1) {

tools/dumpcpp-driver.mjs

@@ -11,7 +11,7 @@ import {
 // Dump C++ symbols of shared library if possible
 
 function processArguments(args) {
-  var processor = new ArgumentsProcessor(args);
+  const processor = new ArgumentsProcessor(args);
   if (processor.parse()) {
     return processor.result();
   } else {
@@ -25,26 +25,26 @@ function initSourceMapSupport() {
 
   // Overwrite the load function to load scripts synchronously.
   SourceMap.load = function(sourceMapURL) {
-    var content = readFile(sourceMapURL);
-    var sourceMapObject = (JSON.parse(content));
+    const content = readFile(sourceMapURL);
+    const sourceMapObject = (JSON.parse(content));
     return new SourceMap(sourceMapURL, sourceMapObject);
   };
 }
 
-var entriesProviders = {
+const entriesProviders = {
   'unix': UnixCppEntriesProvider,
   'windows': WindowsCppEntriesProvider,
   'mac': MacCppEntriesProvider
 };
 
-var params = processArguments(arguments);
-var sourceMap = null;
+const params = processArguments(arguments);
+let sourceMap = null;
 if (params.sourceMap) {
   initSourceMapSupport();
   sourceMap = SourceMap.load(params.sourceMap);
 }
 
-var cppProcessor = new CppProcessor(
+const cppProcessor = new CppProcessor(
   new (entriesProviders[params.platform])(params.nm, params.targetRootFS,
                                           params.apkEmbeddedLibrary),
   params.timedRange, params.pairwiseTimedRange);

tools/dumpcpp.mjs

@@ -33,7 +33,7 @@ export class CppProcessor extends LogReader {
 
   processLogFile(fileName) {
     this.lastLogFileName_ = fileName;
-    var line;
+    let line;
     while (line = readline()) {
       this.processLogLine(line);
     }
@@ -42,26 +42,26 @@ export class CppProcessor extends LogReader {
   processLogFileInTest(fileName) {
     // Hack file name to avoid dealing with platform specifics.
     this.lastLogFileName_ = 'v8.log';
-    var contents = readFile(fileName);
+    const contents = readFile(fileName);
     this.processLogChunk(contents);
   };
 
   processSharedLibrary(name, startAddr, endAddr, aslrSlide) {
-    var self = this;
-    var libFuncs = this.cppEntriesProvider_.parseVmSymbols(
+    const self = this;
+    const libFuncs = this.cppEntriesProvider_.parseVmSymbols(
         name, startAddr, endAddr, aslrSlide, function(fName, fStart, fEnd) {
-      var entry = new CodeEntry(fEnd - fStart, fName, 'CPP');
+      const entry = new CodeEntry(fEnd - fStart, fName, 'CPP');
       self.codeMap_.addStaticCode(fStart, entry);
     });
   };
 
   dumpCppSymbols() {
-    var staticEntries = this.codeMap_.getAllStaticEntriesWithAddresses();
-    var total = staticEntries.length;
-    for (var i = 0; i < total; ++i) {
-      var entry = staticEntries[i];
-      var printValues = ['cpp', '0x' + entry[0].toString(16), entry[1].size,
-                        '"' + entry[1].name + '"'];
+    const staticEntries = this.codeMap_.getAllStaticEntriesWithAddresses();
+    const total = staticEntries.length;
+    for (let i = 0; i < total; ++i) {
+      const entry = staticEntries[i];
+      const printValues = ['cpp', `0x${entry[0].toString(16)}`, entry[1].size,
+                        `"${entry[1].name}"`];
       print(printValues.join(','));
     }
   }

tools/ic-processor-driver.mjs

@@ -7,7 +7,7 @@ import { WebInspector } from "./sourcemap.mjs";
 import { BaseArgumentsProcessor } from "./arguments.mjs";
 
 function processArguments(args) {
-  var processor = new ArgumentsProcessor(args);
+  const processor = new ArgumentsProcessor(args);
   if (processor.parse()) {
     return processor.result();
   } else {
@@ -33,8 +33,8 @@ function initSourceMapSupport() {
 
   // Overwrite the load function to load scripts synchronously.
   SourceMap.load = function(sourceMapURL) {
-    var content = readFile(sourceMapURL);
-    var sourceMapObject = (JSON.parse(content));
+    const content = readFile(sourceMapURL);
+    const sourceMapObject = (JSON.parse(content));
     return new SourceMap(sourceMapURL, sourceMapObject);
   };
 }
@@ -82,7 +82,7 @@ for (const ic of processor.icTimeline.all) {
       ic.type + ' (' + ic.oldState + '->' + ic.newState + ic.modifier + ') at ' +
       ic.filePosition + ' ' + ic.key +
       ' (map 0x' + ic.map.toString(16) + ')' +
-      (ic.reason ? ' ' + ic.reason : '') + ' time: ' + ic.time);
+      (ic.reason ? ` ${ic.reason}` : '') + ' time: ' + ic.time);
   accumulator[ic.type]++;
 }
 

tools/logreader.mjs

@@ -146,11 +146,11 @@ LogReader.prototype.processLogLine = function(line) {
  * @return {Array.<number>} Processed stack.
  */
 LogReader.prototype.processStack = function(pc, func, stack) {
-  var fullStack = func ? [pc, func] : [pc];
-  var prevFrame = pc;
-  for (var i = 0, n = stack.length; i < n; ++i) {
-    var frame = stack[i];
-    var firstChar = frame.charAt(0);
+  const fullStack = func ? [pc, func] : [pc];
+  let prevFrame = pc;
+  for (let i = 0, n = stack.length; i < n; ++i) {
+    const frame = stack[i];
+    const firstChar = frame.charAt(0);
     if (firstChar == '+' || firstChar == '-') {
       // An offset from the previous frame.
       prevFrame += parseInt(frame, 16);
@@ -159,7 +159,7 @@ LogReader.prototype.processStack = function(pc, func, stack) {
     } else if (firstChar != 'o') {
       fullStack.push(parseInt(frame, 16));
     } else {
-      this.printError("dropping: " + frame);
+      this.printError(`dropping: ${frame}`);
     }
   }
   return fullStack;
@@ -172,9 +172,7 @@ LogReader.prototype.processStack = function(pc, func, stack) {
  * @param {!Object} dispatch Dispatch record.
  * @return {boolean} True if dispatch must be skipped.
  */
-LogReader.prototype.skipDispatch = function(dispatch) {
-  return false;
-};
+LogReader.prototype.skipDispatch = dispatch => false;
 
 // Parses dummy variable for readability;
 export const parseString = 'parse-string';
@@ -188,17 +186,17 @@ export const parseVarArgs = 'parse-var-args';
  */
 LogReader.prototype.dispatchLogRow_ = function(fields) {
   // Obtain the dispatch.
-  var command = fields[0];
-  var dispatch = this.dispatchTable_[command];
+  const command = fields[0];
+  const dispatch = this.dispatchTable_[command];
   if (dispatch === undefined) return;
   if (dispatch === null || this.skipDispatch(dispatch)) {
     return;
   }
 
   // Parse fields.
-  var parsedFields = [];
-  for (var i = 0; i < dispatch.parsers.length; ++i) {
-    var parser = dispatch.parsers[i];
+  const parsedFields = [];
+  for (let i = 0; i < dispatch.parsers.length; ++i) {
+    const parser = dispatch.parsers[i];
     if (parser === parseString) {
       parsedFields.push(fields[1 + i]);
     } else if (typeof parser == 'function') {
@@ -208,7 +206,7 @@ LogReader.prototype.dispatchLogRow_ = function(fields) {
       parsedFields.push(fields.slice(1 + i));
       break;
     } else {
-      throw new Error("Invalid log field parser: " + parser);
+      throw new Error(`Invalid log field parser: ${parser}`);
     }
   }
 
@@ -224,7 +222,7 @@ LogReader.prototype.dispatchLogRow_ = function(fields) {
  * @private
  */
 LogReader.prototype.processLog_ = function(lines) {
-  for (var i = 0, n = lines.length; i < n; ++i) {
+  for (let i = 0, n = lines.length; i < n; ++i) {
     this.processLogLine_(lines[i]);
   }
 }
@@ -238,10 +236,10 @@ LogReader.prototype.processLog_ = function(lines) {
 LogReader.prototype.processLogLine_ = function(line) {
   if (line.length > 0) {
     try {
-      var fields = this.csvParser_.parseLine(line);
+      const fields = this.csvParser_.parseLine(line);
       this.dispatchLogRow_(fields);
     } catch (e) {
-      this.printError('line ' + (this.lineNum_ + 1) + ': ' + (e.message || e) + '\n' + e.stack);
+      this.printError(`line ${this.lineNum_ + 1}: ${e.message || e}\n${e.stack}`);
     }
   }
   this.lineNum_++;

tools/parse-processor-driver.mjs

@@ -8,7 +8,7 @@ import {
   } from "./parse-processor.mjs";
 
 function processArguments(args) {
-  var processor = new ArgumentsProcessor(args);
+  const processor = new ArgumentsProcessor(args);
   if (processor.parse()) {
     return processor.result();
   } else {
@@ -22,17 +22,17 @@ function initSourceMapSupport() {
 
   // Overwrite the load function to load scripts synchronously.
   SourceMap.load = function(sourceMapURL) {
-    var content = readFile(sourceMapURL);
-    var sourceMapObject = (JSON.parse(content));
+    const content = readFile(sourceMapURL);
+    const sourceMapObject = (JSON.parse(content));
     return new SourceMap(sourceMapURL, sourceMapObject);
   };
 }
 
-var params = processArguments(arguments);
-var sourceMap = null;
+const params = processArguments(arguments);
+let sourceMap = null;
 if (params.sourceMap) {
   initSourceMapSupport();
   sourceMap = SourceMap.load(params.sourceMap);
 }
-var parseProcessor = new ParseProcessor();
+const parseProcessor = new ParseProcessor();
 parseProcessor.processLogFile(params.logFileName);

tools/parse-processor.mjs

 // Copyright 2017 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-"use strict";
-
 import { LogReader, parseString } from "./logreader.mjs";
 import { BaseArgumentsProcessor } from "./arguments.mjs";
 
@@ -339,7 +337,7 @@ class Script extends CompilationUnit {
 
   calculateMetrics(printSummary) {
     let log = (str) => this.summary += str + '\n';
-    log("SCRIPT: " + this.id);
+    log(`SCRIPT: ${this.id}`);
     let all = this.funktions;
     if (all.length === 0) return;
 
@@ -354,7 +352,7 @@ class Script extends CompilationUnit {
       let value = (funktions.length + "").padStart(6) +
         (nofPercent + "%").padStart(5) +
         BYTES(ownBytes, this.bytesTotal).padStart(10);
-      log(("  - " + name).padEnd(20) + value);
+      log((`  - ${name}`).padEnd(20) + value);
       this.metrics.set(name + "-bytes", ownBytes);
       this.metrics.set(name + "-count", funktions.length);
       this.metrics.set(name + "-count-percent", nofPercent);
@@ -362,7 +360,7 @@ class Script extends CompilationUnit {
         Math.round(ownBytes / this.bytesTotal * 100));
     };
 
-    log("  - file:         " + this.file);
+    log(`  - file:         ${this.file}`);
     log('  - details:      ' +
         'isEval=' + this.isEval + ' deserialized=' + this.isDeserialized +
         ' streamed=' + this.isStreamingCompiled);
@@ -409,7 +407,7 @@ class Script extends CompilationUnit {
     //   [start+delta*2, acc(metric0, start, start+delta*2), ...],
     //   ...
     // ]
-    if (end <= start) throw 'Invalid ranges [' + start + ',' + end + ']';
+    if (end <= start) throw `Invalid ranges [${start},${end}]`;
     const timespan = end - start;
     const kSteps = Math.ceil(timespan / delta);
     // To reduce the time spent iterating over the funktions of this script
@@ -607,8 +605,8 @@ class ExecutionCost {
   }
 
   toString() {
-    return ('  - ' + this.prefix + '-time:').padEnd(24) +
-      (" executed=" + formatNumber(this.executedCost) + 'ms').padEnd(20) +
+    return (`  - ${this.prefix}-time:`).padEnd(24) +
+      (` executed=${formatNumber(this.executedCost)}ms`).padEnd(20) +
       " non-executed=" + formatNumber(this.nonExecutedCost) + 'ms';
   }
 
@@ -623,11 +621,11 @@ class ExecutionCost {
 class Funktion extends CompilationUnit {
   constructor(name, start, end, script) {
     super();
-    if (start < 0) throw "invalid start position: " + start;
+    if (start < 0) throw `invalid start position: ${start}`;
     if (script.isEval) {
       if (end < start) throw 'invalid start end positions';
     } else {
-      if (end <= 0) throw 'invalid end position: ' + end;
+      if (end <= 0) throw `invalid end position: ${end}`;
       if (end <= start) throw 'invalid start end positions';
     }
 
@@ -722,7 +720,7 @@ class Funktion extends CompilationUnit {
   }
 
   toString(details = true) {
-    let result = 'function' + (this.name ? ' ' + this.name : '') +
+    let result = `function${this.name ? ` ${this.name}` : ''}` +
         `() range=${this.start}-${this.end}`;
     if (details) result += ` script=${this.script ? this.script.id : 'X'}`;
     return result;
@@ -841,7 +839,7 @@ export class ParseProcessor extends LogReader {
   processLogFile(fileName) {
     this.collectEntries = true
     this.lastLogFileName_ = fileName;
-    var line;
+    let line;
     while (line = readline()) {
       this.processLogLine(line);
     }
@@ -886,7 +884,7 @@ export class ParseProcessor extends LogReader {
       functionName) {
     let handlerFn = this.functionEventDispatchTable_[eventName];
     if (handlerFn === undefined) {
-      console.error('Couldn\'t find handler for function event:' + eventName);
+      console.error(`Couldn't find handler for function event:${eventName}`);
     }
     handlerFn(
         scriptId, startPosition, endPosition, duration, timestamp,
@@ -965,7 +963,7 @@ export class ParseProcessor extends LogReader {
         script.preparseTimestamp = toTimestamp(timestamp);
         return;
       default:
-        console.error('Unhandled script event: ' + eventName);
+        console.error(`Unhandled script event: ${eventName}`);
     }
   }
 

tools/profile.mjs

@@ -144,7 +144,7 @@ export class Profile {
    * @param {number} endAddr Ending address.
    */
   addLibrary(name, startAddr, endAddr) {
-    var entry = new CodeEntry(endAddr - startAddr, name, 'SHARED_LIB');
+    const entry = new CodeEntry(endAddr - startAddr, name, 'SHARED_LIB');
     this.codeMap_.addLibrary(startAddr, entry);
     return entry;
   }
@@ -157,7 +157,7 @@ export class Profile {
    * @param {number} endAddr Ending address.
    */
   addStaticCode(name, startAddr, endAddr) {
-      var entry = new CodeEntry(endAddr - startAddr, name, 'CPP');
+      const entry = new CodeEntry(endAddr - startAddr, name, 'CPP');
     this.codeMap_.addStaticCode(startAddr, entry);
     return entry;
   }
@@ -171,7 +171,7 @@ export class Profile {
    * @param {number} size Code entry size.
    */
   addCode(type, name, timestamp, start, size) {
-    var entry = new DynamicCodeEntry(size, type, name);
+    const entry = new DynamicCodeEntry(size, type, name);
     this.codeMap_.addCode(start, entry);
     return entry;
   }
@@ -189,7 +189,7 @@ export class Profile {
   addFuncCode(type, name, timestamp, start, size, funcAddr, state) {
     // As code and functions are in the same address space,
     // it is safe to put them in a single code map.
-    var func = this.codeMap_.findDynamicEntryByStartAddress(funcAddr);
+    let func = this.codeMap_.findDynamicEntryByStartAddress(funcAddr);
     if (!func) {
       func = new FunctionEntry(name);
       this.codeMap_.addCode(funcAddr, func);
@@ -197,7 +197,7 @@ export class Profile {
       // Function object has been overwritten with a new one.
       func.name = name;
     }
-    var entry = this.codeMap_.findDynamicEntryByStartAddress(start);
+    let entry = this.codeMap_.findDynamicEntryByStartAddress(start);
     if (entry) {
       if (entry.size === size && entry.func === func) {
         // Entry state has changed.
@@ -297,7 +297,7 @@ export class Profile {
    * @param {Array<number>} stack Stack sample.
    */
   recordTick(time_ns, vmState, stack) {
-    var processedStack = this.resolveAndFilterFuncs_(stack);
+    const processedStack = this.resolveAndFilterFuncs_(stack);
     this.bottomUpTree_.addPath(processedStack);
     processedStack.reverse();
     this.topDownTree_.addPath(processedStack);
@@ -310,13 +310,13 @@ export class Profile {
    * @param {Array<number>} stack Stack sample.
    */
   resolveAndFilterFuncs_(stack) {
-    var result = [];
-    var last_seen_c_function = '';
-    var look_for_first_c_function = false;
-    for (var i = 0; i < stack.length; ++i) {
-      var entry = this.codeMap_.findEntry(stack[i]);
+    const result = [];
+    let last_seen_c_function = '';
+    let look_for_first_c_function = false;
+    for (let i = 0; i < stack.length; ++i) {
+      const entry = this.codeMap_.findEntry(stack[i]);
       if (entry) {
-        var name = entry.getName();
+        const name = entry.getName();
         if (i === 0 && (entry.type === 'CPP' || entry.type === 'SHARED_LIB')) {
           look_for_first_c_function = true;
         }
@@ -393,7 +393,7 @@ export class Profile {
       tree.computeTotalWeights();
       return tree;
     } else {
-      var subTree = tree.cloneSubtree(opt_label);
+      const subTree = tree.cloneSubtree(opt_label);
       subTree.computeTotalWeights();
       return subTree;
     }
@@ -406,11 +406,11 @@ export class Profile {
    * @param {string} opt_label Starting node label.
    */
   getFlatProfile(opt_label) {
-    var counters = new CallTree();
-    var rootLabel = opt_label || CallTree.ROOT_NODE_LABEL;
-    var precs = {};
+    const counters = new CallTree();
+    const rootLabel = opt_label || CallTree.ROOT_NODE_LABEL;
+    const precs = {};
     precs[rootLabel] = 0;
-    var root = counters.findOrAddChild(rootLabel);
+    const root = counters.findOrAddChild(rootLabel);
 
     this.topDownTree_.computeTotalWeights();
     this.topDownTree_.traverseInDepth(
@@ -418,13 +418,13 @@ export class Profile {
         if (!(node.label in precs)) {
           precs[node.label] = 0;
         }
-        var nodeLabelIsRootLabel = node.label == rootLabel;
+        const nodeLabelIsRootLabel = node.label == rootLabel;
         if (nodeLabelIsRootLabel || precs[rootLabel] > 0) {
           if (precs[rootLabel] == 0) {
             root.selfWeight += node.selfWeight;
             root.totalWeight += node.totalWeight;
           } else {
-            var rec = root.findOrAddChild(node.label);
+            const rec = root.findOrAddChild(node.label);
             rec.selfWeight += node.selfWeight;
             if (nodeLabelIsRootLabel || precs[node.label] == 0) {
               rec.totalWeight += node.totalWeight;
@@ -454,17 +454,15 @@ export class Profile {
   }
 
   getCEntryProfile() {
-    var result = [new CEntryNode("TOTAL", 0)];
-    var total_ticks = 0;
-    for (var f in this.c_entries_) {
-      var ticks = this.c_entries_[f];
+    const result = [new CEntryNode("TOTAL", 0)];
+    let total_ticks = 0;
+    for (let f in this.c_entries_) {
+      const ticks = this.c_entries_[f];
       total_ticks += ticks;
       result.push(new CEntryNode(f, ticks));
     }
     result[0].ticks = total_ticks;  // Sorting will keep this at index 0.
-    result.sort(function (n1, n2) {
-      return n2.ticks - n1.ticks || (n2.name < n1.name ? -1 : 1)
-    });
+    result.sort((n1, n2) => n2.ticks - n1.ticks || (n2.name < n1.name ? -1 : 1));
     return result;
   }
 
@@ -473,19 +471,19 @@ export class Profile {
    * Cleans up function entries that are not referenced by code entries.
    */
   cleanUpFuncEntries() {
-    var referencedFuncEntries = [];
-    var entries = this.codeMap_.getAllDynamicEntriesWithAddresses();
-    for (var i = 0, l = entries.length; i < l; ++i) {
+    const referencedFuncEntries = [];
+    const entries = this.codeMap_.getAllDynamicEntriesWithAddresses();
+    for (let i = 0, l = entries.length; i < l; ++i) {
       if (entries[i][1].constructor === FunctionEntry) {
         entries[i][1].used = false;
       }
     }
-    for (var i = 0, l = entries.length; i < l; ++i) {
+    for (let i = 0, l = entries.length; i < l; ++i) {
       if ("func" in entries[i][1]) {
         entries[i][1].func.used = true;
       }
     }
-    for (var i = 0, l = entries.length; i < l; ++i) {
+    for (let i = 0, l = entries.length; i < l; ++i) {
       if (entries[i][1].constructor === FunctionEntry &&
         !entries[i][1].used) {
         this.codeMap_.deleteCode(entries[i][0]);
@@ -556,9 +554,9 @@ class DynamicFuncCodeEntry extends CodeEntry {
   getState() {
     return DynamicFuncCodeEntry.STATE_PREFIX[this.state];
   }
-  
+
   getName() {
-    var name = this.func.getName();
+    const name = this.func.getName();
     return this.type + ': ' + this.getState() + name;
   }
 
@@ -593,12 +591,12 @@ class FunctionEntry extends CodeEntry {
    * Returns node name.
    */
   getName() {
-    var name = this.name;
+    let name = this.name;
     if (name.length == 0) {
       name = '<anonymous>';
     } else if (name.charAt(0) == ' ') {
       // An anonymous function with location: " aaa.js:10".
-      name = '<anonymous>' + name;
+      name = `<anonymous>${name}`;
     }
     return name;
   }
@@ -634,8 +632,8 @@ class CallTree {
     if (path.length == 0) {
       return;
     }
-    var curr = this.root_;
-    for (var i = 0; i < path.length; ++i) {
+    let curr = this.root_;
+    for (let i = 0; i < path.length; ++i) {
       curr = curr.findOrAddChild(path[i]);
     }
     curr.selfWeight++;
@@ -670,12 +668,12 @@ class CallTree {
    * @param {string} label The label of the new root node.
    */
   cloneSubtree(label) {
-    var subTree = new CallTree();
+    const subTree = new CallTree();
     this.traverse((node, parent) => {
       if (!parent && node.label != label) {
         return null;
       }
-      var child = (parent ? parent : subTree).findOrAddChild(node.label);
+      const child = (parent ? parent : subTree).findOrAddChild(node.label);
       child.selfWeight += node.selfWeight;
       return child;
     });
@@ -707,13 +705,13 @@ class CallTree {
    *    The second parameter is the result of calling 'f' on the parent node.
    */
   traverse(f) {
-    var pairsToProcess = new ConsArray();
+    const pairsToProcess = new ConsArray();
     pairsToProcess.concat([{ node: this.root_, param: null }]);
     while (!pairsToProcess.atEnd()) {
-      var pair = pairsToProcess.next();
-      var node = pair.node;
-      var newParam = f(node, pair.param);
-      var morePairsToProcess = [];
+      const pair = pairsToProcess.next();
+      const node = pair.node;
+      const newParam = f(node, pair.param);
+      const morePairsToProcess = [];
       node.forEachChild((child) => {
         morePairsToProcess.push({ node: child, param: newParam });
       });
@@ -773,7 +771,7 @@ class CallTree {
    * @param {string} label Child node label.
    */
   addChild(label) {
-    var child = new CallTreeNode(label, this);
+    const child = new CallTreeNode(label, this);
     this.children[label] = child;
     return child;
   }
@@ -782,7 +780,7 @@ class CallTree {
    * Computes node's total weight.
    */
   computeTotalWeight() {
-    var totalWeight = this.selfWeight;
+    let totalWeight = this.selfWeight;
     this.forEachChild(function (child) {
       totalWeight += child.computeTotalWeight();
     });
@@ -793,7 +791,7 @@ class CallTree {
    * Returns all node's children as an array.
    */
   exportChildren() {
-    var result = [];
+    const result = [];
     this.forEachChild(function (node) { result.push(node); });
     return result;
   }
@@ -823,7 +821,7 @@ class CallTree {
    * @param {function(CallTreeNode)} f Visitor function.
    */
   forEachChild(f) {
-    for (var c in this.children) {
+    for (let c in this.children) {
       f(this.children[c]);
     }
   }
@@ -834,7 +832,7 @@ class CallTree {
    * @param {function(CallTreeNode)} f Visitor function.
    */
   walkUpToRoot(f) {
-    for (var curr = this; curr != null; curr = curr.parent) {
+    for (let curr = this; curr != null; curr = curr.parent) {
       f(curr);
     }
   }
@@ -846,8 +844,9 @@ class CallTree {
    * @param {function(CallTreeNode)} opt_f Visitor function.
    */
   descendToChild(labels, opt_f) {
-    for (var pos = 0, curr = this; pos < labels.length && curr != null; pos++) {
-      var child = curr.findChild(labels[pos]);
+    let curr = this;
+    for (let pos = 0; pos < labels.length && curr != null; pos++) {
+      const child = curr.findChild(labels[pos]);
       if (opt_f) {
         opt_f(child, pos);
       }
@@ -867,7 +866,7 @@ export function JsonProfile() {
 
 JsonProfile.prototype.addLibrary = function (
   name, startAddr, endAddr) {
-  var entry = new CodeEntry(
+  const entry = new CodeEntry(
     endAddr - startAddr, name, 'SHARED_LIB');
   this.codeMap_.addLibrary(startAddr, entry);
 
@@ -878,7 +877,7 @@ JsonProfile.prototype.addLibrary = function (
 
 JsonProfile.prototype.addStaticCode = function (
   name, startAddr, endAddr) {
-  var entry = new CodeEntry(
+  const entry = new CodeEntry(
     endAddr - startAddr, name, 'CPP');
   this.codeMap_.addStaticCode(startAddr, entry);
 
@@ -897,7 +896,7 @@ JsonProfile.prototype.addCode = function (
     codeId = staticEntry.entry.codeId;
   }
 
-  var entry = new CodeEntry(size, name, 'CODE');
+  const entry = new CodeEntry(size, name, 'CODE');
   this.codeMap_.addCode(start, entry);
 
   entry.codeId = codeId;
@@ -905,7 +904,7 @@ JsonProfile.prototype.addCode = function (
     name: entry.name,
     timestamp: timestamp,
     type: entry.type,
-    kind: kind
+    kind: kind,
   };
 
   return entry;
@@ -915,22 +914,22 @@ JsonProfile.prototype.addFuncCode = function (
   kind, name, timestamp, start, size, funcAddr, state) {
   // As code and functions are in the same address space,
   // it is safe to put them in a single code map.
-  var func = this.codeMap_.findDynamicEntryByStartAddress(funcAddr);
+  let func = this.codeMap_.findDynamicEntryByStartAddress(funcAddr);
   if (!func) {
-    var func = new CodeEntry(0, name, 'SFI');
+    func = new CodeEntry(0, name, 'SFI');
     this.codeMap_.addCode(funcAddr, func);
 
     func.funcId = this.functionEntries_.length;
-    this.functionEntries_.push({ name: name, codes: [] });
+    this.functionEntries_.push({ name, codes: [] });
   } else if (func.name !== name) {
     // Function object has been overwritten with a new one.
     func.name = name;
 
     func.funcId = this.functionEntries_.length;
-    this.functionEntries_.push({ name: name, codes: [] });
+    this.functionEntries_.push({ name, codes: [] });
   }
   // TODO(jarin): Insert the code object into the SFI's code list.
-  var entry = this.codeMap_.findDynamicEntryByStartAddress(start);
+  let entry = this.codeMap_.findDynamicEntryByStartAddress(start);
   if (entry) {
     if (entry.size === size && entry.func === func) {
       // Entry state has changed.
@@ -961,7 +960,7 @@ JsonProfile.prototype.addFuncCode = function (
       type: entry.type,
       kind: kind,
       func: func.funcId,
-      tm: timestamp
+      tm: timestamp,
     });
   }
   return entry;
@@ -971,25 +970,25 @@ JsonProfile.prototype.moveCode = function (from, to) {
   try {
     this.codeMap_.moveCode(from, to);
   } catch (e) {
-    printErr("Move: unknown source " + from);
+    printErr(`Move: unknown source ${from}`);
   }
 };
 
 JsonProfile.prototype.addSourcePositions = function (
   start, script, startPos, endPos, sourcePositions, inliningPositions,
   inlinedFunctions) {
-  var entry = this.codeMap_.findDynamicEntryByStartAddress(start);
+  const entry = this.codeMap_.findDynamicEntryByStartAddress(start);
   if (!entry) return;
-  var codeId = entry.codeId;
+  const codeId = entry.codeId;
 
   // Resolve the inlined functions list.
   if (inlinedFunctions.length > 0) {
     inlinedFunctions = inlinedFunctions.substring(1).split("S");
-    for (var i = 0; i < inlinedFunctions.length; i++) {
-      var funcAddr = parseInt(inlinedFunctions[i]);
-      var func = this.codeMap_.findDynamicEntryByStartAddress(funcAddr);
+    for (let i = 0; i < inlinedFunctions.length; i++) {
+      const funcAddr = parseInt(inlinedFunctions[i]);
+      const func = this.codeMap_.findDynamicEntryByStartAddress(funcAddr);
       if (!func || func.funcId === undefined) {
-        printErr("Could not find function " + inlinedFunctions[i]);
+        printErr(`Could not find function ${inlinedFunctions[i]}`);
         inlinedFunctions[i] = null;
       } else {
         inlinedFunctions[i] = func.funcId;
@@ -1029,7 +1028,7 @@ JsonProfile.prototype.deoptCode = function (
         scriptOffset: scriptOffset,
         posText: sourcePositionText,
         reason: deoptReasonText,
-        bailoutType: bailoutType
+        bailoutType: bailoutType,
       };
     }
   }
@@ -1039,7 +1038,7 @@ JsonProfile.prototype.deleteCode = function (start) {
   try {
     this.codeMap_.deleteCode(start);
   } catch (e) {
-    printErr("Delete: unknown address " + start);
+    printErr(`Delete: unknown address ${start}`);
   }
 };
 
@@ -1056,9 +1055,9 @@ JsonProfile.prototype.findEntry = function (addr) {
 JsonProfile.prototype.recordTick = function (time_ns, vmState, stack) {
   // TODO(jarin) Resolve the frame-less case (when top of stack is
   // known code).
-  var processedStack = [];
-  for (var i = 0; i < stack.length; i++) {
-    var resolved = this.codeMap_.findAddress(stack[i]);
+  const processedStack = [];
+  for (let i = 0; i < stack.length; i++) {
+    const resolved = this.codeMap_.findAddress(stack[i]);
     if (resolved) {
       processedStack.push(resolved.entry.codeId, resolved.offset);
     } else {
@@ -1086,7 +1085,7 @@ JsonProfile.prototype.writeJson = function () {
   write(',\n');
 
   write('  "ticks": [\n');
-  for (var i = 0; i < this.ticks_.length; i++) {
+  for (let i = 0; i < this.ticks_.length; i++) {
     write('    ');
     writeJson(this.ticks_[i]);
     if (i < this.ticks_.length - 1) {

tools/profile_view.mjs

@@ -47,12 +47,12 @@ export function ViewBuilder(samplingRate) {
  */
 ViewBuilder.prototype.buildView = function(
     callTree, opt_bottomUpViewWeights) {
-  var head;
-  var samplingRate = this.samplingRate;
-  var createViewNode = this.createViewNode;
+  let head;
+  const samplingRate = this.samplingRate;
+  const createViewNode = this.createViewNode;
   callTree.traverse(function(node, viewParent) {
-    var totalWeight = node.totalWeight * samplingRate;
-    var selfWeight = node.selfWeight * samplingRate;
+    const totalWeight = node.totalWeight * samplingRate;
+    let selfWeight = node.selfWeight * samplingRate;
     if (opt_bottomUpViewWeights === true) {
       if (viewParent === head) {
         selfWeight = totalWeight;
@@ -60,7 +60,7 @@ ViewBuilder.prototype.buildView = function(
         selfWeight = 0;
       }
     }
-    var viewNode = createViewNode(node.label, totalWeight, selfWeight, head);
+    const viewNode = createViewNode(node.label, totalWeight, selfWeight, head);
     if (viewParent) {
       viewParent.addChild(viewNode);
     } else {
@@ -68,7 +68,7 @@ ViewBuilder.prototype.buildView = function(
     }
     return viewNode;
   });
-  var view = this.createView(head);
+  const view = this.createView(head);
   return view;
 };
 
@@ -79,9 +79,7 @@ ViewBuilder.prototype.buildView = function(
  * @param {ProfileView.Node} head View head node.
  * @return {ProfileView} Profile view.
  */
-ViewBuilder.prototype.createView = function(head) {
-  return new ProfileView(head);
-};
+ViewBuilder.prototype.createView = head => new ProfileView(head);
 
 
 /**
@@ -96,11 +94,11 @@ ViewBuilder.prototype.createView = function(head) {
  * @param {ProfileView.Node} head Profile view head.
  * @return {ProfileView.Node} Profile view node.
  */
-ViewBuilder.prototype.createViewNode = function(
-    funcName, totalTime, selfTime, head) {
-  return new ProfileView.Node(
-      funcName, totalTime, selfTime, head);
-};
+ViewBuilder.prototype.createViewNode = (
+    funcName, totalTime, selfTime, head) =>
+  new ProfileView.Node(
+      funcName, totalTime, selfTime, head)
+;
 
 
 /**
@@ -135,10 +133,10 @@ ProfileView.prototype.sort = function(sortFunc) {
  * @param {function(ProfileView.Node)} f Visitor function.
  */
 ProfileView.prototype.traverse = function(f) {
-  var nodesToTraverse = new ConsArray();
+  const nodesToTraverse = new ConsArray();
   nodesToTraverse.concat([this.head]);
   while (!nodesToTraverse.atEnd()) {
-    var node = nodesToTraverse.next();
+    const node = nodesToTraverse.next();
     f(node);
     nodesToTraverse.concat(node.children);
   }

tools/sourcemap.mjs

@@ -77,7 +77,7 @@ WebInspector.SourceMap = function(sourceMappingURL, payload)
     if (!WebInspector.SourceMap.prototype._base64Map) {
         const base64Digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
         WebInspector.SourceMap.prototype._base64Map = {};
-        for (var i = 0; i < base64Digits.length; ++i)
+        for (let i = 0; i < base64Digits.length; ++i)
             WebInspector.SourceMap.prototype._base64Map[base64Digits.charAt(i)] = i;
     }
 
@@ -107,7 +107,7 @@ WebInspector.SourceMap.load = function(sourceMapURL, compiledURL, callback)
     function contentLoaded(error, statusCode, headers, content)
     {
         if (error || !content || statusCode >= 400) {
-            console.error("Could not load content for " + sourceMapURL + " : " + (error || ("HTTP status code: " + statusCode)));
+            console.error(`Could not load content for ${sourceMapURL} : ${error || (`HTTP status code: ${statusCode}`)}`);
             callback(null);
             return;
         }
@@ -115,8 +115,8 @@ WebInspector.SourceMap.load = function(sourceMapURL, compiledURL, callback)
         if (content.slice(0, 3) === ")]}")
             content = content.substring(content.indexOf('\n'));
         try {
-            var payload = /** @type {SourceMapV3} */ (JSON.parse(content));
-            var baseURL = sourceMapURL.startsWith("data:") ? compiledURL : sourceMapURL;
+            const payload = /** @type {SourceMapV3} */ (JSON.parse(content));
+            const baseURL = sourceMapURL.startsWith("data:") ? compiledURL : sourceMapURL;
             callback(new WebInspector.SourceMap(baseURL, payload));
         } catch(e) {
             console.error(e.message);
@@ -129,7 +129,7 @@ WebInspector.SourceMap.prototype = {
     /**
      * @return {Array.<string>}
      */
-    sources: function()
+    sources()
     {
         return Object.keys(this._sources);
     },
@@ -138,7 +138,7 @@ WebInspector.SourceMap.prototype = {
      * @param {string} sourceURL
      * @return {string|undefined}
      */
-    sourceContent: function(sourceURL)
+    sourceContent(sourceURL)
     {
         return this._sourceContentByURL[sourceURL];
     },
@@ -148,12 +148,12 @@ WebInspector.SourceMap.prototype = {
      * @param {WebInspector.ResourceType} contentType
      * @return {WebInspector.ContentProvider}
      */
-    sourceContentProvider: function(sourceURL, contentType)
+    sourceContentProvider(sourceURL, contentType)
     {
-        var lastIndexOfDot = sourceURL.lastIndexOf(".");
-        var extension = lastIndexOfDot !== -1 ? sourceURL.substr(lastIndexOfDot + 1) : "";
-        var mimeType = WebInspector.ResourceType.mimeTypesForExtensions[extension.toLowerCase()];
-        var sourceContent = this.sourceContent(sourceURL);
+        const lastIndexOfDot = sourceURL.lastIndexOf(".");
+        const extension = lastIndexOfDot !== -1 ? sourceURL.substr(lastIndexOfDot + 1) : "";
+        const mimeType = WebInspector.ResourceType.mimeTypesForExtensions[extension.toLowerCase()];
+        const sourceContent = this.sourceContent(sourceURL);
         if (sourceContent)
             return new WebInspector.StaticContentProvider(contentType, sourceContent, mimeType);
         return new WebInspector.CompilerSourceMappingContentProvider(sourceURL, contentType, mimeType);
@@ -162,7 +162,7 @@ WebInspector.SourceMap.prototype = {
     /**
      * @param {SourceMapV3} mappingPayload
      */
-    _parseMappingPayload: function(mappingPayload)
+    _parseMappingPayload(mappingPayload)
     {
         if (mappingPayload.sections)
             this._parseSections(mappingPayload.sections);
@@ -173,10 +173,10 @@ WebInspector.SourceMap.prototype = {
     /**
      * @param {Array.<SourceMapV3.Section>} sections
      */
-    _parseSections: function(sections)
+    _parseSections(sections)
     {
-        for (var i = 0; i < sections.length; ++i) {
-            var section = sections[i];
+        for (let i = 0; i < sections.length; ++i) {
+            const section = sections[i];
             this._parseMap(section.map, section.offset.line, section.offset.column);
         }
     },
@@ -186,14 +186,14 @@ WebInspector.SourceMap.prototype = {
      * @param {number} columnNumber in compiled resource
      * @return {?Array}
      */
-    findEntry: function(lineNumber, columnNumber)
+    findEntry(lineNumber, columnNumber)
     {
-        var first = 0;
-        var count = this._mappings.length;
+        let first = 0;
+        let count = this._mappings.length;
         while (count > 1) {
-          var step = count >> 1;
-          var middle = first + step;
-          var mapping = this._mappings[middle];
+          const step = count >> 1;
+          const middle = first + step;
+          const mapping = this._mappings[middle];
           if (lineNumber < mapping[0] || (lineNumber === mapping[0] && columnNumber < mapping[1]))
               count = step;
           else {
@@ -201,7 +201,7 @@ WebInspector.SourceMap.prototype = {
               count -= step;
           }
         }
-        var entry = this._mappings[first];
+        const entry = this._mappings[first];
         if (!first && entry && (lineNumber < entry[0] || (lineNumber === entry[0] && columnNumber < entry[1])))
             return null;
         return entry;
@@ -212,11 +212,11 @@ WebInspector.SourceMap.prototype = {
      * @param {number} lineNumber in the originating resource
      * @return {Array}
      */
-    findEntryReversed: function(sourceURL, lineNumber)
+    findEntryReversed(sourceURL, lineNumber)
     {
-        var mappings = this._reverseMappingsBySourceURL[sourceURL];
+        const mappings = this._reverseMappingsBySourceURL[sourceURL];
         for ( ; lineNumber < mappings.length; ++lineNumber) {
-            var mapping = mappings[lineNumber];
+            const mapping = mappings[lineNumber];
             if (mapping)
                 return mapping;
         }
@@ -226,32 +226,32 @@ WebInspector.SourceMap.prototype = {
     /**
      * @override
      */
-    _parseMap: function(map, lineNumber, columnNumber)
+    _parseMap(map, lineNumber, columnNumber)
     {
-        var sourceIndex = 0;
-        var sourceLineNumber = 0;
-        var sourceColumnNumber = 0;
-        var nameIndex = 0;
-
-        var sources = [];
-        var originalToCanonicalURLMap = {};
-        for (var i = 0; i < map.sources.length; ++i) {
-            var originalSourceURL = map.sources[i];
-            var sourceRoot = map.sourceRoot || "";
-            if (sourceRoot && !sourceRoot.endsWith("/"))
-                sourceRoot += "/";
-            var href = sourceRoot + originalSourceURL;
-            var url = WebInspector.ParsedURL.completeURL(this._sourceMappingURL, href) || href;
+        let sourceIndex = 0;
+        let sourceLineNumber = 0;
+        let sourceColumnNumber = 0;
+        let nameIndex = 0;
+
+        const sources = [];
+        const originalToCanonicalURLMap = {};
+        for (let i = 0; i < map.sources.length; ++i) {
+            const originalSourceURL = map.sources[i];
+            let sourceRoot = map.sourceRoot || "";
+            if (sourceRoot && !sourceRoot.endsWith("/")) sourceRoot += "/";
+            const href = sourceRoot + originalSourceURL;
+            const url = WebInspector.ParsedURL.completeURL(this._sourceMappingURL, href) || href;
             originalToCanonicalURLMap[originalSourceURL] = url;
             sources.push(url);
             this._sources[url] = true;
 
-            if (map.sourcesContent && map.sourcesContent[i])
+            if (map.sourcesContent && map.sourcesContent[i]) {
                 this._sourceContentByURL[url] = map.sourcesContent[i];
+            }
         }
 
-        var stringCharIterator = new WebInspector.SourceMap.StringCharIterator(map.mappings);
-        var sourceURL = sources[sourceIndex];
+        const stringCharIterator = new WebInspector.SourceMap.StringCharIterator(map.mappings);
+        let sourceURL = sources[sourceIndex];
 
         while (true) {
             if (stringCharIterator.peek() === ",")
@@ -272,7 +272,7 @@ WebInspector.SourceMap.prototype = {
                 continue;
             }
 
-            var sourceIndexDelta = this._decodeVLQ(stringCharIterator);
+            const sourceIndexDelta = this._decodeVLQ(stringCharIterator);
             if (sourceIndexDelta) {
                 sourceIndex += sourceIndexDelta;
                 sourceURL = sources[sourceIndex];
@@ -285,17 +285,18 @@ WebInspector.SourceMap.prototype = {
             this._mappings.push([lineNumber, columnNumber, sourceURL, sourceLineNumber, sourceColumnNumber]);
         }
 
-        for (var i = 0; i < this._mappings.length; ++i) {
-            var mapping = this._mappings[i];
-            var url = mapping[2];
-            if (!url)
-                continue;
-            if (!this._reverseMappingsBySourceURL[url])
+        for (let i = 0; i < this._mappings.length; ++i) {
+            const mapping = this._mappings[i];
+            const url = mapping[2];
+            if (!url) continue;
+            if (!this._reverseMappingsBySourceURL[url]) {
                 this._reverseMappingsBySourceURL[url] = [];
-            var reverseMappings = this._reverseMappingsBySourceURL[url];
-            var sourceLine = mapping[3];
-            if (!reverseMappings[sourceLine])
+            }
+            const reverseMappings = this._reverseMappingsBySourceURL[url];
+            const sourceLine = mapping[3];
+            if (!reverseMappings[sourceLine]) {
                 reverseMappings[sourceLine] = [mapping[0], mapping[1]];
+            }
         }
     },
 
@@ -303,7 +304,7 @@ WebInspector.SourceMap.prototype = {
      * @param {string} char
      * @return {boolean}
      */
-    _isSeparator: function(char)
+    _isSeparator(char)
     {
         return char === "," || char === ";";
     },
@@ -312,19 +313,20 @@ WebInspector.SourceMap.prototype = {
      * @param {WebInspector.SourceMap.StringCharIterator} stringCharIterator
      * @return {number}
      */
-    _decodeVLQ: function(stringCharIterator)
+    _decodeVLQ(stringCharIterator)
     {
         // Read unsigned value.
-        var result = 0;
-        var shift = 0;
+        let result = 0;
+        let shift = 0;
+        let digit;
         do {
-            var digit = this._base64Map[stringCharIterator.next()];
+            digit = this._base64Map[stringCharIterator.next()];
             result += (digit & this._VLQ_BASE_MASK) << shift;
             shift += this._VLQ_BASE_SHIFT;
         } while (digit & this._VLQ_CONTINUATION_MASK);
 
         // Fix the sign.
-        var negative = result & 1;
+        const negative = result & 1;
         // Use unsigned right shift, so that the 32nd bit is properly shifted
         // to the 31st, and the 32nd becomes unset.
         result >>>= 1;
@@ -359,7 +361,7 @@ WebInspector.SourceMap.StringCharIterator.prototype = {
     /**
      * @return {string}
      */
-    next: function()
+    next()
     {
         return this._string.charAt(this._position++);
     },
@@ -367,7 +369,7 @@ WebInspector.SourceMap.StringCharIterator.prototype = {
     /**
      * @return {string}
      */
-    peek: function()
+    peek()
     {
         return this._string.charAt(this._position);
     },
@@ -375,7 +377,7 @@ WebInspector.SourceMap.StringCharIterator.prototype = {
     /**
      * @return {boolean}
      */
-    hasNext: function()
+    hasNext()
     {
         return this._position < this._string.length;
     }

tools/splaytree.mjs

@@ -75,7 +75,7 @@ SplayTree.prototype.insert = function(key, value) {
   if (this.root_.key == key) {
     return;
   }
-  var node = new SplayTree.Node(key, value);
+  const node = new SplayTree.Node(key, value);
   if (key > this.root_.key) {
     node.left = this.root_;
     node.right = this.root_.right;
@@ -99,17 +99,17 @@ SplayTree.prototype.insert = function(key, value) {
  */
 SplayTree.prototype.remove = function(key) {
   if (this.isEmpty()) {
-    throw Error('Key not found: ' + key);
+    throw Error(`Key not found: ${key}`);
   }
   this.splay_(key);
   if (this.root_.key != key) {
-    throw Error('Key not found: ' + key);
+    throw Error(`Key not found: ${key}`);
   }
-  var removed = this.root_;
+  const removed = this.root_;
   if (!this.root_.left) {
     this.root_ = this.root_.right;
   } else {
-    var right = this.root_.right;
+    const { right } = this.root_;
     this.root_ = this.root_.left;
     // Splay to make sure that the new root has an empty right child.
     this.splay_(key);
@@ -144,7 +144,7 @@ SplayTree.prototype.findMin = function() {
   if (this.isEmpty()) {
     return null;
   }
-  var current = this.root_;
+  let current = this.root_;
   while (current.left) {
     current = current.left;
   }
@@ -159,7 +159,7 @@ SplayTree.prototype.findMax = function(opt_startNode) {
   if (this.isEmpty()) {
     return null;
   }
-  var current = opt_startNode || this.root_;
+  let current = opt_startNode || this.root_;
   while (current.right) {
     current = current.right;
   }
@@ -195,7 +195,7 @@ SplayTree.prototype.findGreatestLessThan = function(key) {
  *     with keys.
  */
 SplayTree.prototype.exportKeysAndValues = function() {
-  var result = [];
+  const result = [];
   this.traverse_(function(node) { result.push([node.key, node.value]); });
   return result;
 };
@@ -205,7 +205,7 @@ SplayTree.prototype.exportKeysAndValues = function() {
  * @return {Array<*>} An array containing all the values of tree's nodes.
  */
 SplayTree.prototype.exportValues = function() {
-  var result = [];
+  const result = [];
   this.traverse_(function(node) { result.push(node.value); });
   return result;
 };
@@ -230,9 +230,9 @@ SplayTree.prototype.splay_ = function(key) {
   // the L tree of the algorithm.  The left child of the dummy node
   // will hold the R tree of the algorithm.  Using a dummy node, left
   // and right will always be nodes and we avoid special cases.
-  var dummy, left, right;
+  let dummy, left, right;
   dummy = left = right = new SplayTree.Node(null, null);
-  var current = this.root_;
+  let current = this.root_;
   while (true) {
     if (key < current.key) {
       if (!current.left) {
@@ -240,7 +240,7 @@ SplayTree.prototype.splay_ = function(key) {
       }
       if (key < current.left.key) {
         // Rotate right.
-        var tmp = current.left;
+        const tmp = current.left;
         current.left = tmp.right;
         tmp.right = current;
         current = tmp;
@@ -258,7 +258,7 @@ SplayTree.prototype.splay_ = function(key) {
       }
       if (key > current.right.key) {
         // Rotate left.
-        var tmp = current.right;
+        const tmp = current.right;
         current.right = tmp.left;
         tmp.left = current;
         current = tmp;
@@ -290,9 +290,9 @@ SplayTree.prototype.splay_ = function(key) {
  * @private
  */
 SplayTree.prototype.traverse_ = function(f) {
-  var nodesToVisit = [this.root_];
+  const nodesToVisit = [this.root_];
   while (nodesToVisit.length > 0) {
-    var node = nodesToVisit.shift();
+    const node = nodesToVisit.shift();
     if (node == null) {
       continue;
     }

tools/system-analyzer/ic-panel.mjs

@@ -55,16 +55,15 @@ DOM.defineCustomElement(
       }
 
       updateCount() {
-        this.count.innerHTML = 'length=' + this._selectedLogEntries.length;
+        this.count.innerHTML = `length=${this._selectedLogEntries.length}`;
       }
 
       updateTable(event) {
         let select = this.groupKey;
         let key = select.options[select.selectedIndex].text;
-        let tableBody = this.tableBody;
-        DOM.removeAllChildren(tableBody);
+        DOM.removeAllChildren(this.tableBody);
         let groups = Group.groupBy(this._selectedLogEntries, key, true);
-        this.render(groups, tableBody);
+        this.render(groups, this.tableBody);
       }
 
       escapeHtml(unsafe) {
@@ -89,8 +88,7 @@ DOM.defineCustomElement(
         // searches for mapLogEntries using the id, time
         const selectedMapLogEntriesSet = new Set();
         for (const icLogEntry of icLogEntries) {
-          const time = icLogEntry.time;
-          const selectedMap = MapLogEntry.get(id, time);
+          const selectedMap = MapLogEntry.get(id, icLogEntry.time);
           selectedMapLogEntriesSet.add(selectedMap);
         }
         return Array.from(selectedMapLogEntriesSet);
@@ -131,8 +129,7 @@ DOM.defineCustomElement(
         const omitted = groups.length - max;
         if (omitted > 0) {
           const tr = DOM.tr();
-          const tdNode =
-              tr.appendChild(DOM.td('Omitted ' + omitted + ' entries.'));
+          const tdNode = tr.appendChild(DOM.td(`Omitted ${omitted} entries.`));
           tdNode.colSpan = 4;
           fragment.appendChild(tr);
         }

tools/system-analyzer/log-file-reader.mjs

@@ -38,7 +38,7 @@ DOM.defineCustomElement('log-file-reader',
     event.preventDefault();
     this.dispatchEvent(
         new CustomEvent('fileuploadstart', {bubbles: true, composed: true}));
-    var host = event.dataTransfer ? event.dataTransfer : event.target;
+    const host = event.dataTransfer ? event.dataTransfer : event.target;
     this.readFile(host.files[0]);
   }
 
@@ -73,7 +73,7 @@ DOM.defineCustomElement('log-file-reader',
 
   handleFileLoad(e, file) {
     const chunk = e.target.result;
-    this.updateLabel('Finished loading \'' + file.name + '\'.');
+    this.updateLabel(`Finished loading '${file.name}'.`);
     this.dispatchEvent(new CustomEvent('fileuploadend', {
       bubbles: true,
       composed: true,

tools/system-analyzer/log/map.mjs

@@ -184,9 +184,9 @@ class Edge {
   }
 
   finishSetup() {
-    let from = this.from;
+    const from = this.from;
     if (from) from.addEdge(this);
-    let to = this.to;
+    const to = this.to;
     if (to === undefined) return;
     to.edge = this;
     if (from === undefined) return;

tools/system-analyzer/map-panel/map-details.mjs

@@ -29,9 +29,9 @@ DOM.defineCustomElement(
         let details = '';
         let clickableDetails = '';
         if (map) {
-          clickableDetails += 'ID: ' + map.id;
-          clickableDetails += '\nSource location: ' + map.filePosition;
-          details += '\n' + map.description;
+          clickableDetails += `ID: ${map.id}`;
+          clickableDetails += `\nSource location: ${map.filePosition}`;
+          details += `\n${map.description}`;
           this.setSelectedMap(map);
         }
         this._filePositionNode.innerText = clickableDetails;

tools/system-analyzer/map-panel/map-transitions.mjs

@@ -39,7 +39,7 @@ DOM.defineCustomElement('./map-panel/map-transitions',
   handleTransitionViewChange(e) {
     this.tooltip.style.left = e.pageX + 'px';
     this.tooltip.style.top = e.pageY + 'px';
-    let map = e.target.map;
+    const map = e.target.map;
     if (map) {
       this.tooltipContents.innerText = map.description;
     }

tools/system-analyzer/processor.mjs

@@ -125,7 +125,7 @@ export class Processor extends LogReader {
         this.processLogLine(line);
       }
     } catch (e) {
-      console.error('Error occurred during parsing, trying to continue: ' + e);
+      console.error(`Error occurred during parsing, trying to continue: ${e}`);
     }
     this.finalize();
   }
@@ -142,7 +142,7 @@ export class Processor extends LogReader {
       }
     } catch (e) {
       console.error(
-          'Error occurred during parsing line ' + i +
+          `Error occurred during parsing line ${i}` +
           ', trying to continue: ' + e);
     }
     this.finalize();
@@ -155,8 +155,8 @@ export class Processor extends LogReader {
     this._mapTimeline.forEach(map => {
       if (map.isRoot()) id = map.finalizeRootMap(id + 1);
       if (map.edge && map.edge.name) {
-        let edge = map.edge;
-        let list = this._mapTimeline.transitions.get(edge.name);
+        const edge = map.edge;
+        const list = this._mapTimeline.transitions.get(edge.name);
         if (list === undefined) {
           this._mapTimeline.transitions.set(edge.name, [edge]);
         } else {
@@ -178,13 +178,13 @@ export class Processor extends LogReader {
       case '*':
         return Profile.CodeState.OPTIMIZED;
     }
-    throw new Error('unknown code state: ' + s);
+    throw new Error(`unknown code state: ${s}`);
   }
 
   processCodeCreation(type, kind, timestamp, start, size, name, maybe_func) {
     if (maybe_func.length) {
-      let funcAddr = parseInt(maybe_func[0]);
-      let state = this.parseState(maybe_func[1]);
+      const funcAddr = parseInt(maybe_func[0]);
+      const state = this.parseState(maybe_func[1]);
       this._profile.addFuncCode(
           type, name, timestamp, start, size, funcAddr, state);
     } else {
@@ -324,7 +324,7 @@ export class Processor extends LogReader {
     if (id === '0x000000000000') return undefined;
     let map = MapLogEntry.get(id, time);
     if (map === undefined) {
-      console.error('No map details provided: id=' + id);
+      console.error(`No map details provided: id=${id}`);
       // Manually patch in a map to continue running.
       return this.createMapEntry(id, time);
     };

tools/system-analyzer/source-panel.mjs

@@ -188,12 +188,11 @@ class LineBuilder {
     this._selection = new Set(highlightPositions);
     this._clickHandler = panel.handleSourcePositionClick.bind(panel);
     // TODO: sort on script finalization.
-    script.sourcePositions
-        .sort((a, b) => {
-          if (a.line === b.line) return a.column - b.column;
-          return a.line - b.line;
-        }) this._sourcePositions =
-        new SourcePositionIterator(script.sourcePositions);
+    script.sourcePositions.sort((a, b) => {
+      if (a.line === b.line) return a.column - b.column;
+      return a.line - b.line;
+    });
+    this._sourcePositions = new SourcePositionIterator(script.sourcePositions);
   }
 
   get sourcePositionToMarkers() {

tools/system-analyzer/timeline/timeline-track.mjs

@@ -220,7 +220,6 @@ DOM.defineCustomElement('./timeline/timeline-track',
   }
 
   renderLegend() {
-    let timelineLegend = this.timelineLegend;
     let timelineLegendContent = this.timelineLegendContent;
     DOM.removeAllChildren(timelineLegendContent);
     this._timeline.uniqueTypes.forEach((entries, type) => {
@@ -249,7 +248,7 @@ DOM.defineCustomElement('./timeline/timeline-track',
     row.appendChild(DOM.td(this.data.all.length));
     row.appendChild(DOM.td('100%'));
     timelineLegendContent.appendChild(row);
-    timelineLegend.appendChild(timelineLegendContent);
+    this.timelineLegend.appendChild(timelineLegendContent);
   }
 
   handleEntryTypeDblClick(e) {
@@ -306,7 +305,7 @@ DOM.defineCustomElement('./timeline/timeline-track',
     }
 
     let imageData = this.backgroundCanvas.toDataURL('image/webp', 0.2);
-    node.style.backgroundImage = 'url(' + imageData + ')';
+    node.style.backgroundImage = `url(${imageData})`;
   }
 
   updateTimeline() {

tools/tickprocessor-driver.mjs

@@ -34,7 +34,7 @@ import {
 // Tick Processor's code flow.
 
 function processArguments(args) {
-  var processor = new ArgumentsProcessor(args);
+  const processor = new ArgumentsProcessor(args);
   if (processor.parse()) {
     return processor.result();
   } else {
@@ -48,25 +48,25 @@ function initSourceMapSupport() {
 
   // Overwrite the load function to load scripts synchronously.
   SourceMap.load = function(sourceMapURL) {
-    var content = readFile(sourceMapURL);
-    var sourceMapObject = (JSON.parse(content));
+    const content = readFile(sourceMapURL);
+    const sourceMapObject = (JSON.parse(content));
     return new SourceMap(sourceMapURL, sourceMapObject);
   };
 }
 
-var entriesProviders = {
+const entriesProviders = {
   'unix': UnixCppEntriesProvider,
   'windows': WindowsCppEntriesProvider,
   'mac': MacCppEntriesProvider
 };
 
-var params = processArguments(arguments);
-var sourceMap = null;
+const params = processArguments(arguments);
+let sourceMap = null;
 if (params.sourceMap) {
   initSourceMapSupport();
   sourceMap = SourceMap.load(params.sourceMap);
 }
-var tickProcessor = new TickProcessor(
+const tickProcessor = new TickProcessor(
   new (entriesProviders[params.platform])(params.nm, params.objdump, params.targetRootFS,
                                           params.apkEmbeddedLibrary),
   params.separateIc,

tools/tickprocessor.mjs

@@ -45,14 +45,14 @@ class V8Profile extends Profile {
 
   constructor(separateIc, separateBytecodes, separateBuiltins, separateStubs) {
     super();
-    var regexps = [];
+    const regexps = [];
     if (!separateIc) regexps.push(V8Profile.IC_RE);
     if (!separateBytecodes) regexps.push(V8Profile.BYTECODES_RE);
     if (!separateBuiltins) regexps.push(V8Profile.BUILTINS_RE);
     if (!separateStubs) regexps.push(V8Profile.STUBS_RE);
     if (regexps.length > 0) {
       this.skipThisFunction = function(name) {
-        for (var i=0; i<regexps.length; i++) {
+        for (let i=0; i<regexps.length; i++) {
           if (regexps[i].test(name)) return true;
         }
         return false;
@@ -84,7 +84,7 @@ function parseState(s) {
   case "~": return Profile.CodeState.OPTIMIZABLE;
   case "*": return Profile.CodeState.OPTIMIZED;
   }
-  throw new Error("unknown code state: " + s);
+  throw new Error(`unknown code state: ${s}`);
 }
 
 
@@ -165,29 +165,29 @@ export function TickProcessor(
   this.stateFilter_ = stateFilter;
   this.runtimeTimerFilter_ = runtimeTimerFilter;
   this.sourceMap = sourceMap;
-  var ticks = this.ticks_ =
+  const ticks = this.ticks_ =
     { total: 0, unaccounted: 0, excluded: 0, gc: 0 };
 
   distortion = parseInt(distortion);
   // Convert picoseconds to nanoseconds.
   this.distortion_per_entry = isNaN(distortion) ? 0 : (distortion / 1000);
   this.distortion = 0;
-  var rangelimits = range ? range.split(",") : [];
-  var range_start = parseInt(rangelimits[0]);
-  var range_end = parseInt(rangelimits[1]);
+  const rangelimits = range ? range.split(",") : [];
+  const range_start = parseInt(rangelimits[0]);
+  const range_end = parseInt(rangelimits[1]);
   // Convert milliseconds to nanoseconds.
   this.range_start = isNaN(range_start) ? -Infinity : (range_start * 1000);
   this.range_end = isNaN(range_end) ? Infinity : (range_end * 1000)
 
   V8Profile.prototype.handleUnknownCode = function(
       operation, addr, opt_stackPos) {
-    var op = Profile.Operation;
+    const op = Profile.Operation;
     switch (operation) {
       case op.MOVE:
-        printErr('Code move event for unknown code: 0x' + addr.toString(16));
+        printErr(`Code move event for unknown code: 0x${addr.toString(16)}`);
         break;
       case op.DELETE:
-        printErr('Code delete event for unknown code: 0x' + addr.toString(16));
+        printErr(`Code delete event for unknown code: 0x${addr.toString(16)}`);
         break;
       case op.TICK:
         // Only unknown PCs (the first frame) are reported as unaccounted,
@@ -272,7 +272,7 @@ TickProcessor.prototype.isJsCode = function(name) {
 
 TickProcessor.prototype.processLogFile = function(fileName) {
   this.lastLogFileName_ = fileName;
-  var line;
+  let line;
   while (line = readline()) {
     this.processLogLine(line);
   }
@@ -282,18 +282,18 @@ TickProcessor.prototype.processLogFile = function(fileName) {
 TickProcessor.prototype.processLogFileInTest = function(fileName) {
    // Hack file name to avoid dealing with platform specifics.
   this.lastLogFileName_ = 'v8.log';
-  var contents = readFile(fileName);
+  const contents = readFile(fileName);
   this.processLogChunk(contents);
 };
 
 
 TickProcessor.prototype.processSharedLibrary = function(
     name, startAddr, endAddr, aslrSlide) {
-  var entry = this.profile_.addLibrary(name, startAddr, endAddr, aslrSlide);
+  const entry = this.profile_.addLibrary(name, startAddr, endAddr, aslrSlide);
   this.setCodeType(entry.getName(), 'SHARED_LIB');
 
-  var self = this;
-  var libFuncs = this.cppEntriesProvider_.parseVmSymbols(
+  const self = this;
+  const libFuncs = this.cppEntriesProvider_.parseVmSymbols(
       name, startAddr, endAddr, aslrSlide, function(fName, fStart, fEnd) {
     self.profile_.addStaticCode(fName, fStart, fEnd);
     self.setCodeType(fName, 'CPP');
@@ -304,8 +304,8 @@ TickProcessor.prototype.processSharedLibrary = function(
 TickProcessor.prototype.processCodeCreation = function(
     type, kind, timestamp, start, size, name, maybe_func) {
   if (maybe_func.length) {
-    var funcAddr = parseInt(maybe_func[0]);
-    var state = parseState(maybe_func[1]);
+    const funcAddr = parseInt(maybe_func[0]);
+    const state = parseState(maybe_func[1]);
     this.profile_.addFuncCode(type, name, timestamp, start, size, funcAddr, state);
   } else {
     this.profile_.addCode(type, name, timestamp, start, size);
@@ -385,7 +385,7 @@ TickProcessor.prototype.processTick = function(pc,
   } else if (tos_or_external_callback) {
     // Find out, if top of stack was pointing inside a JS function
     // meaning that we have encountered a frameless invocation.
-    var funcEntry = this.profile_.findEntry(tos_or_external_callback);
+    const funcEntry = this.profile_.findEntry(tos_or_external_callback);
     if (!funcEntry || !funcEntry.isJSFunction || !funcEntry.isJSFunction()) {
       tos_or_external_callback = 0;
     }
@@ -411,14 +411,14 @@ TickProcessor.prototype.processHeapSampleBegin = function(space, state, ticks) {
 TickProcessor.prototype.processHeapSampleEnd = function(space, state) {
   if (space != 'Heap' || !this.currentProducerProfile_) return;
 
-  print('Generation ' + this.generation_ + ':');
-  var tree = this.currentProducerProfile_;
+  print(`Generation ${this.generation_}:`);
+  const tree = this.currentProducerProfile_;
   tree.computeTotalWeights();
-  var producersView = this.viewBuilder_.buildView(tree);
+  const producersView = this.viewBuilder_.buildView(tree);
   // Sort by total time, desc, then by name, desc.
-  producersView.sort(function(rec1, rec2) {
-      return rec2.totalTime - rec1.totalTime ||
-          (rec2.internalFuncName < rec1.internalFuncName ? -1 : 1); });
+  producersView.sort((rec1, rec2) =>
+      rec2.totalTime - rec1.totalTime ||
+          (rec2.internalFuncName < rec1.internalFuncName ? -1 : 1) );
   this.printHeavyProfile(producersView.head.children);
 
   this.currentProducerProfile_ = null;
@@ -432,46 +432,46 @@ TickProcessor.prototype.printStatistics = function() {
     return;
   }
 
-  print('Statistical profiling result from ' + this.lastLogFileName_ +
+  print(`Statistical profiling result from ${this.lastLogFileName_}` +
         ', (' + this.ticks_.total +
         ' ticks, ' + this.ticks_.unaccounted + ' unaccounted, ' +
         this.ticks_.excluded + ' excluded).');
 
   if (this.ticks_.total == 0) return;
 
-  var flatProfile = this.profile_.getFlatProfile();
-  var flatView = this.viewBuilder_.buildView(flatProfile);
+  const flatProfile = this.profile_.getFlatProfile();
+  const flatView = this.viewBuilder_.buildView(flatProfile);
   // Sort by self time, desc, then by name, desc.
-  flatView.sort(function(rec1, rec2) {
-      return rec2.selfTime - rec1.selfTime ||
-          (rec2.internalFuncName < rec1.internalFuncName ? -1 : 1); });
-  var totalTicks = this.ticks_.total;
+  flatView.sort((rec1, rec2) =>
+      rec2.selfTime - rec1.selfTime ||
+          (rec2.internalFuncName < rec1.internalFuncName ? -1 : 1) );
+  let totalTicks = this.ticks_.total;
   if (this.ignoreUnknown_) {
     totalTicks -= this.ticks_.unaccounted;
   }
-  var printAllTicks = !this.onlySummary_;
+  const printAllTicks = !this.onlySummary_;
 
   // Count library ticks
-  var flatViewNodes = flatView.head.children;
-  var self = this;
+  const flatViewNodes = flatView.head.children;
+  const self = this;
 
-  var libraryTicks = 0;
+  let libraryTicks = 0;
   if(printAllTicks) this.printHeader('Shared libraries');
   this.printEntries(flatViewNodes, totalTicks, null,
-      function(name) { return self.isSharedLibrary(name); },
+      name => self.isSharedLibrary(name),
       function(rec) { libraryTicks += rec.selfTime; }, printAllTicks);
-  var nonLibraryTicks = totalTicks - libraryTicks;
+  const nonLibraryTicks = totalTicks - libraryTicks;
 
-  var jsTicks = 0;
+  let jsTicks = 0;
   if(printAllTicks) this.printHeader('JavaScript');
   this.printEntries(flatViewNodes, totalTicks, nonLibraryTicks,
-      function(name) { return self.isJsCode(name); },
+      name => self.isJsCode(name),
       function(rec) { jsTicks += rec.selfTime; }, printAllTicks);
 
-  var cppTicks = 0;
+  let cppTicks = 0;
   if(printAllTicks) this.printHeader('C++');
   this.printEntries(flatViewNodes, totalTicks, nonLibraryTicks,
-      function(name) { return self.isCppCode(name); },
+      name => self.isCppCode(name),
       function(rec) { cppTicks += rec.selfTime; }, printAllTicks);
 
   this.printHeader('Summary');
@@ -487,22 +487,22 @@ TickProcessor.prototype.printStatistics = function() {
   if(printAllTicks) {
     print('\n [C++ entry points]:');
     print('   ticks    cpp   total   name');
-    var c_entry_functions = this.profile_.getCEntryProfile();
-    var total_c_entry = c_entry_functions[0].ticks;
-    for (var i = 1; i < c_entry_functions.length; i++) {
+    const c_entry_functions = this.profile_.getCEntryProfile();
+    const total_c_entry = c_entry_functions[0].ticks;
+    for (let i = 1; i < c_entry_functions.length; i++) {
       const c = c_entry_functions[i];
       this.printLine(c.name, c.ticks, total_c_entry, totalTicks);
     }
 
     this.printHeavyProfHeader();
-    var heavyProfile = this.profile_.getBottomUpProfile();
-    var heavyView = this.viewBuilder_.buildView(heavyProfile);
+    const heavyProfile = this.profile_.getBottomUpProfile();
+    const heavyView = this.viewBuilder_.buildView(heavyProfile);
     // To show the same percentages as in the flat profile.
     heavyView.head.totalTime = totalTicks;
     // Sort by total time, desc, then by name, desc.
-    heavyView.sort(function(rec1, rec2) {
-        return rec2.totalTime - rec1.totalTime ||
-            (rec2.internalFuncName < rec1.internalFuncName ? -1 : 1); });
+    heavyView.sort((rec1, rec2) =>
+        rec2.totalTime - rec1.totalTime ||
+            (rec2.internalFuncName < rec1.internalFuncName ? -1 : 1) );
     this.printHeavyProfile(heavyView.head.children);
   }
 };
@@ -511,7 +511,7 @@ TickProcessor.prototype.printStatistics = function() {
 function padLeft(s, len) {
   s = s.toString();
   if (s.length < len) {
-    var padLength = len - s.length;
+    const padLength = len - s.length;
     if (!(padLength in padLeft)) {
       padLeft[padLength] = new Array(padLength + 1).join(' ');
     }
@@ -522,18 +522,18 @@ function padLeft(s, len) {
 
 
 TickProcessor.prototype.printHeader = function(headerTitle) {
-  print('\n [' + headerTitle + ']:');
+  print(`\n [${headerTitle}]:`);
   print('   ticks  total  nonlib   name');
 };
 
 
 TickProcessor.prototype.printLine = function(
     entry, ticks, totalTicks, nonLibTicks) {
-  var pct = ticks * 100 / totalTicks;
-  var nonLibPct = nonLibTicks != null
+  const pct = ticks * 100 / totalTicks;
+  const nonLibPct = nonLibTicks != null
       ? padLeft((ticks * 100 / nonLibTicks).toFixed(1), 5) + '%  '
       : '        ';
-  print('  ' + padLeft(ticks, 5) + '  ' +
+  print(`  ${padLeft(ticks, 5)}  ` +
         padLeft(pct.toFixed(1), 5) + '%  ' +
         nonLibPct +
         entry);
@@ -553,8 +553,8 @@ TickProcessor.prototype.printHeavyProfHeader = function() {
 
 TickProcessor.prototype.processProfile = function(
     profile, filterP, func) {
-  for (var i = 0, n = profile.length; i < n; ++i) {
-    var rec = profile[i];
+  for (let i = 0, n = profile.length; i < n; ++i) {
+    const rec = profile[i];
     if (!filterP(rec.internalFuncName)) {
       continue;
     }
@@ -563,8 +563,8 @@ TickProcessor.prototype.processProfile = function(
 };
 
 TickProcessor.prototype.getLineAndColumn = function(name) {
-  var re = /:([0-9]+):([0-9]+)$/;
-  var array = re.exec(name);
+  const re = /:([0-9]+):([0-9]+)$/;
+  const array = re.exec(name);
   if (!array) {
     return null;
   }
@@ -580,28 +580,28 @@ TickProcessor.prototype.formatFunctionName = function(funcName) {
   if (!this.hasSourceMap()) {
     return funcName;
   }
-  var lc = this.getLineAndColumn(funcName);
+  const lc = this.getLineAndColumn(funcName);
   if (lc == null) {
     return funcName;
   }
   // in source maps lines and columns are zero based
-  var lineNumber = lc.line - 1;
-  var column = lc.column - 1;
-  var entry = this.sourceMap.findEntry(lineNumber, column);
-  var sourceFile = entry[2];
-  var sourceLine = entry[3] + 1;
-  var sourceColumn = entry[4] + 1;
+  const lineNumber = lc.line - 1;
+  const column = lc.column - 1;
+  const entry = this.sourceMap.findEntry(lineNumber, column);
+  const sourceFile = entry[2];
+  const sourceLine = entry[3] + 1;
+  const sourceColumn = entry[4] + 1;
 
   return sourceFile + ':' + sourceLine + ':' + sourceColumn + ' -> ' + funcName;
 };
 
 TickProcessor.prototype.printEntries = function(
     profile, totalTicks, nonLibTicks, filterP, callback, printAllTicks) {
-  var that = this;
+  const that = this;
   this.processProfile(profile, filterP, function (rec) {
     if (rec.selfTime == 0) return;
     callback(rec);
-    var funcName = that.formatFunctionName(rec.internalFuncName);
+    const funcName = that.formatFunctionName(rec.internalFuncName);
     if(printAllTicks) {
       that.printLine(funcName, rec.selfTime, totalTicks, nonLibTicks);
     }
@@ -610,14 +610,14 @@ TickProcessor.prototype.printEntries = function(
 
 
 TickProcessor.prototype.printHeavyProfile = function(profile, opt_indent) {
-  var self = this;
-  var indent = opt_indent || 0;
-  var indentStr = padLeft('', indent);
-  this.processProfile(profile, function() { return true; }, function (rec) {
+  const self = this;
+  const indent = opt_indent || 0;
+  const indentStr = padLeft('', indent);
+  this.processProfile(profile, () => true, function (rec) {
     // Cut off too infrequent callers.
     if (rec.parentTotalPercent < TickProcessor.CALL_PROFILE_CUTOFF_PCT) return;
-    var funcName = self.formatFunctionName(rec.internalFuncName);
-    print('  ' + padLeft(rec.totalTime, 5) + '  ' +
+    const funcName = self.formatFunctionName(rec.internalFuncName);
+    print(`  ${padLeft(rec.totalTime, 5)}  ` +
           padLeft(rec.parentTotalPercent.toFixed(1), 5) + '%  ' +
           indentStr + funcName);
     // Limit backtrace depth.
@@ -640,8 +640,8 @@ CppEntriesProvider.prototype.parseVmSymbols = function(
     libName, libStart, libEnd, libASLRSlide, processorFunc) {
   this.loadSymbols(libName);
 
-  var lastUnknownSize;
-  var lastAdded;
+  let lastUnknownSize;
+  let lastAdded;
 
   function inRange(funcInfo, start, end) {
     return funcInfo.start >= start && funcInfo.end <= end;
@@ -681,7 +681,7 @@ CppEntriesProvider.prototype.parseVmSymbols = function(
   }
 
   while (true) {
-    var funcInfo = this.parseNextLine();
+    const funcInfo = this.parseNextLine();
     if (funcInfo === null) {
       continue;
     } else if (funcInfo === false) {
@@ -706,9 +706,7 @@ CppEntriesProvider.prototype.loadSymbols = function(libName) {
 };
 
 
-CppEntriesProvider.prototype.parseNextLine = function() {
-  return false;
-};
+CppEntriesProvider.prototype.parseNextLine = () => false;
 
 
 export function UnixCppEntriesProvider(nmExec, objdumpExec, targetRootFS, apkEmbeddedLibrary) {
@@ -759,17 +757,17 @@ UnixCppEntriesProvider.prototype.parseNextLine = function() {
   if (this.symbols.length == 0) {
     return false;
   }
-  var lineEndPos = this.symbols[0].indexOf('\n', this.parsePos);
+  const lineEndPos = this.symbols[0].indexOf('\n', this.parsePos);
   if (lineEndPos == -1) {
     this.symbols.shift();
     this.parsePos = 0;
     return this.parseNextLine();
   }
 
-  var line = this.symbols[0].substring(this.parsePos, lineEndPos);
+  const line = this.symbols[0].substring(this.parsePos, lineEndPos);
   this.parsePos = lineEndPos + 1;
-  var fields = line.match(this.FUNC_RE);
-  var funcInfo = null;
+  const fields = line.match(this.FUNC_RE);
+  let funcInfo = null;
   if (fields) {
     funcInfo = { name: fields[3], start: parseInt(fields[1], 16) + this.fileOffsetMinusVma };
     if (fields[2]) {
@@ -829,9 +827,9 @@ WindowsCppEntriesProvider.EXE_IMAGE_BASE = 0x00400000;
 
 WindowsCppEntriesProvider.prototype.loadSymbols = function(libName) {
   libName = this.targetRootFS + libName;
-  var fileNameFields = libName.match(WindowsCppEntriesProvider.FILENAME_RE);
+  const fileNameFields = libName.match(WindowsCppEntriesProvider.FILENAME_RE);
   if (!fileNameFields) return;
-  var mapFileName = fileNameFields[1] + '.map';
+  const mapFileName = fileNameFields[1] + '.map';
   this.moduleType_ = fileNameFields[2].toLowerCase();
   try {
     this.symbols = read(mapFileName);
@@ -843,26 +841,26 @@ WindowsCppEntriesProvider.prototype.loadSymbols = function(libName) {
 
 
 WindowsCppEntriesProvider.prototype.parseNextLine = function() {
-  var lineEndPos = this.symbols.indexOf('\r\n', this.parsePos);
+  const lineEndPos = this.symbols.indexOf('\r\n', this.parsePos);
   if (lineEndPos == -1) {
     return false;
   }
 
-  var line = this.symbols.substring(this.parsePos, lineEndPos);
+  const line = this.symbols.substring(this.parsePos, lineEndPos);
   this.parsePos = lineEndPos + 2;
 
   // Image base entry is above all other symbols, so we can just
   // terminate parsing.
-  var imageBaseFields = line.match(WindowsCppEntriesProvider.IMAGE_BASE_RE);
+  const imageBaseFields = line.match(WindowsCppEntriesProvider.IMAGE_BASE_RE);
   if (imageBaseFields) {
-    var imageBase = parseInt(imageBaseFields[1], 16);
+    const imageBase = parseInt(imageBaseFields[1], 16);
     if ((this.moduleType_ == 'exe') !=
         (imageBase == WindowsCppEntriesProvider.EXE_IMAGE_BASE)) {
       return false;
     }
   }
 
-  var fields = line.match(WindowsCppEntriesProvider.FUNC_RE);
+  const fields = line.match(WindowsCppEntriesProvider.FUNC_RE);
   return fields ?
       { name: this.unmangleName(fields[1]), start: parseInt(fields[2], 16) } :
       null;
@@ -880,8 +878,8 @@ WindowsCppEntriesProvider.prototype.parseNextLine = function() {
 WindowsCppEntriesProvider.prototype.unmangleName = function(name) {
   // Empty or non-mangled name.
   if (name.length < 1 || name.charAt(0) != '?') return name;
-  var nameEndPos = name.indexOf('@@');
-  var components = name.substring(1, nameEndPos).split('@');
+  const nameEndPos = name.indexOf('@@');
+  const components = name.substring(1, nameEndPos).split('@');
   components.reverse();
   return components.join('::');
 };