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Make build.js automatically remove unused variables from builds.

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Former-commit-id: 03c9e77498263da0f5dc10bc9076a74d471d93f9
This commit is contained in:
John-David Dalton
2013-06-16 00:04:02 -07:00
parent 25b216d7ef
commit 5040ec109b
1 changed files with 120 additions and 71 deletions
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191
build.js
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@@ -17,21 +17,21 @@
/** The current working directory */
var cwd = process.cwd();
/** Used for array method references */
var arrayRef = Array.prototype;
/** Used for array and object method references */
var arrayRef = Array.prototype,
objectRef = Object.prototype;
/** Shortcut used to push arrays of values to an array */
var push = arrayRef.push;
/** Native method shortcuts */
var hasOwnProperty = objectRef.hasOwnProperty,
push = arrayRef.push,
slice = arrayRef.slice;
/** Used to create regexes that may detect multi-line comment blocks */
var multilineComment = '(?:\\n +/\\*[^*]*\\*+(?:[^/][^*]*\\*+)*/)?\\n';
var multilineComment = '(?:\\n */\\*[^*]*\\*+(?:[^/][^*]*\\*+)*/)?\\n';
/** Used to detect the Node.js executable in command-line arguments */
var reNode = RegExp('(?:^|' + path.sepEscaped + ')node(?:\\.exe)?$');
/** Shortcut used to convert array-like objects to arrays */
var slice = arrayRef.slice;
/** Shortcut to the `stdout` object */
var stdout = process.stdout;
@@ -687,7 +687,9 @@
// consolidate consecutive horizontal rule comment separators
.replace(/(?:\s*\/\*-+\*\/\s*){2,}/g, function(separators) {
return separators.match(/^\s*/)[0] + separators.slice(separators.lastIndexOf('/*'));
});
})
// remove unneeded horizontal rule comment separators
.replace(/(\{\n)\s*\/\*-+\*\/\n/g, '$1');
}
/**
@@ -747,8 +749,9 @@
* @returns {Array} Returns an array of aliases.
*/
function getAliases(methodName) {
return (realToAliasMap[methodName] || []).filter(function(methodName) {
return !dependencyMap[methodName];
var aliases = hasOwnProperty.call(realToAliasMap, methodName) && realToAliasMap[methodName];
return _.filter(aliases, function(methodName) {
return !hasOwnProperty.call(dependencyMap, methodName);
});
}
@@ -824,7 +827,10 @@
* @returns {Array} Returns an array of method dependencies.
*/
function getDependencies(methodName, stack) {
var dependencies = _.isArray(methodName) ? methodName : dependencyMap[methodName];
var dependencies = _.isArray(methodName)
? methodName
: (hasOwnProperty.call(dependencyMap, methodName) && dependencyMap[methodName]);
if (!dependencies) {
return [];
}
@@ -965,7 +971,61 @@
* @returns {String} Returns the real method name.
*/
function getRealName(methodName) {
return (!dependencyMap[methodName] && aliasToRealMap[methodName]) || methodName;
return (
!hasOwnProperty.call(dependencyMap, methodName) &&
hasOwnProperty.call(aliasToRealMap, methodName) &&
aliasToRealMap[methodName]
) || methodName;
}
/**
* Gets the number of times a given variable is referenced in `source`.
*
* @private
* @param {String} source The source to process.
* @param {String} varName The name of the variable.
* @returns {Number} Returns the number of times `varName` is referenced.
*/
function getRefCount(source, varName) {
var indentA = isRemoved(source, 'runInContext') ? ' {2}' : ' {2,4}',
indentB = isRemoved(source, 'runInContext') ? ' {6}' : ' {6,8}',
snippet = source.replace(/^ *(?:\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/|\/\/.+)\n/gm, '');
var match = RegExp(
'^(' + indentA + ')var ' + varName + ' *(?:|= *(?:.+?(?:|&&\\n[^;]+)|(?:\\w+\\(|[{(]\\n)[\\s\\S]+?\\n\\1[^\\n ]+?));\\n|' +
'^' + indentA + 'var ' + varName + ' *=.+?,\\n(?= *\\w+ *=)|' +
'^' + indentB + varName + ' *=.+?[,;]\\n'
,'m')
.exec(snippet);
if (match) {
snippet = snippet.slice(0, match.index) + snippet.slice(match.index + match[0].length);
}
return _.size(match && snippet.match(RegExp('[^.\\w]' + varName + '\\b', 'g')));
}
/**
* Gets all variables defined outside of Lo-Dash methods.
*
* @private
* @param {String} source The source to process.
* @returns {Array} Returns a new array of variable names.
*/
function getVars(source) {
var indentA = isRemoved(source, 'runInContext') ? ' {2}' : ' {2,4}',
indentB = isRemoved(source, 'runInContext') ? ' {6}' : ' {6,8}',
snippet = source.replace(/^ *(?:\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/|\/\/.+)\n/gm, ''),
result = [];
snippet.replace(RegExp(
'^(' + indentA + ')var (\\w+) *(?:|= *(?:.+?(?:|&&\\n[^;]+)|(?:\\w+\\(|[{(]\\n)[\\s\\S]+?\\n\\1[^\\n ]+?));\\n|' +
'^' + indentA + 'var (\\w+) *=.+?,\\n(?= *\\w+ *=)|' +
'^' + indentB + '(\\w+) *=.+?[,;]\\n'
,'gm'), function(match, indent, varA, varB, varC) {
result.push(varA || varB || varC);
});
return _.uniq(result).sort();
}
/**
@@ -1585,26 +1645,25 @@
*/
function removeVar(source, varName) {
// simplify complex variable assignments
if (/^(?:cloneableClasses|contextProps|ctorByClass|nonEnumProps|shadowedProps|whitespace)$/.test(varName)) {
source = source.replace(RegExp('(var ' + varName + ' *=)[\\s\\S]+?;\\n\\n'), '$1=null;\n\n');
if (/^(?:cloneableClasses|contextProps|ctorByClass|freeGlobal|nonEnumProps|shadowedProps|whitespace)$/.test(varName)) {
source = source.replace(RegExp('(var ' + varName + ' *=)[\\s\\S]+?[;}]\\n\\n'), '$1=null;\n\n');
}
source = removeFunction(source, varName);
// match a variable declaration that's not part of a declaration list
source = source.replace(RegExp(
multilineComment +
// match a variable declaration that's not part of a declaration list
'( *)var ' + varName + ' *= *(?:.+?(?:;|&&\\n[^;]+;)|(?:\\w+\\(|{)[\\s\\S]+?\\n\\1.+?;)\\n|' +
// match a variable in a declaration list
'^ *' + varName + ' *=.+?,\\n',
'm'
'( *)var ' + varName + ' *(?:|= *(?:.+?(?:|&&\\n[^;]+)|(?:\\w+\\(|[{(]\\n)[\\s\\S]+?\\n\\1[^\\n ]+?));\\n'
), '');
// remove a varaible at the start of a variable declaration list
source = source.replace(RegExp('(var +)' + varName + ' *=.+?,\\s+'), '$1');
// match a variable declaration in a declaration list
source = source.replace(RegExp(
'( *(?:var +)?\\w+ *=.+?),\\n *' + varName + ' *=.+?([,;])(?=\\n)'
), '$1$2');
// remove a variable at the end of a variable declaration list
source = source.replace(RegExp(',\\s*' + varName + ' *=.+?;'), ';');
// remove a varaible at the start of a declaration list
source = source.replace(RegExp('(var +)' + varName + ' *=.+?,\\n *'), '$1');
return source;
}
@@ -2126,7 +2185,7 @@
/*------------------------------------------------------------------------*/
// load customized Lo-Dash module
var lodash = !isTemplate && (function() {
var lodash = !isModularize && !isTemplate && (function() {
source = setUseStrictOption(source, isStrict);
if (isLegacy) {
@@ -3199,27 +3258,13 @@
/*------------------------------------------------------------------------*/
// customize Lo-Dash's IIFE
(function() {
if (isIIFE) {
var token = '%output%',
index = iife.indexOf(token);
source = source.match(/^\/\**[\s\S]+?\*\/\n/) +
iife.slice(0, index) +
source.replace(/^[\s\S]+?\(function[^{]+?{|}\(this\)\)[;\s]*$/g, '') +
iife.slice(index + token.length);
}
}());
/*------------------------------------------------------------------------*/
// customize Lo-Dash's export bootstrap
(function() {
if (!isAMD) {
source = source.replace(/(?: *\/\/.*\n)*( *)if *\(typeof +define[\s\S]+?else /, '$1');
}
if (!isNode) {
source = removeVar(source, 'freeGlobal');
source = source.replace(/(?: *\/\/.*\n)*( *)if *\(freeModule[\s\S]+?else *{([\s\S]+?\n)\1}\n+/, '$1$2');
}
if (!isCommonJS) {
@@ -3238,6 +3283,21 @@
/*------------------------------------------------------------------------*/
// customize Lo-Dash's IIFE
(function() {
if (isIIFE) {
var token = '%output%',
index = iife.indexOf(token);
source = source.match(/^\/\**[\s\S]+?\*\/\n/) +
iife.slice(0, index) +
source.replace(/^[\s\S]+?\(function[^{]+?{|}\(this\)\)[;\s]*$/g, '') +
iife.slice(index + token.length);
}
}());
/*------------------------------------------------------------------------*/
// modify/remove references to removed methods/variables
if (!isTemplate) {
if (isRemoved(source, 'clone')) {
@@ -3248,39 +3308,18 @@
source = removeSupportNodeClass(source);
}
if (isRemoved(source, 'createIterator')) {
source = removeVar(source, 'defaultsIteratorOptions');
source = removeVar(source, 'eachIteratorOptions');
source = removeVar(source, 'forOwnIteratorOptions');
source = removeVar(source, 'iteratorTemplate');
source = removeVar(source, 'templateIterator');
source = removeSupportNonEnumShadows(source);
}
if (isRemoved(source, 'createIterator', 'bind', 'keys')) {
source = removeSupportProp(source, 'fastBind');
source = removeVar(source, 'isV8');
source = removeVar(source, 'nativeBind');
}
if (isRemoved(source, 'createIterator', 'keys')) {
source = removeVar(source, 'nativeKeys');
source = removeKeysOptimization(source);
source = removeSupportNonEnumArgs(source);
}
if (isRemoved(source, 'defer')) {
source = removeSetImmediate(source);
}
if (isRemoved(source, 'escape', 'unescape')) {
source = removeVar(source, 'htmlEscapes');
source = removeVar(source, 'htmlUnescapes');
}
if (isRemoved(source, 'getArray', 'releaseArray')) {
source = removeVar(source, 'arrayPool');
}
if (isRemoved(source, 'getObject', 'releaseObject')) {
source = removeVar(source, 'objectPool');
}
if (isRemoved(source, 'releaseArray', 'releaseObject')) {
source = removeVar(source, 'maxPoolSize');
}
if (isRemoved(source, 'invert')) {
source = replaceVar(source, 'htmlUnescapes', "{'&amp;':'&','&lt;':'<','&gt;':'>','&quot;':'\"','&#x27;':\"'\"}");
}
@@ -3291,12 +3330,9 @@
source = removeSupportArgsClass(source);
}
if (isRemoved(source, 'isArray')) {
source = removeVar(source, 'nativeIsArray');
source = removeIsArrayFallback(source);
}
if (isRemoved(source, 'isPlainObject')) {
source = removeFunction(source, 'shimIsPlainObject');
source = removeVar(source, 'getPrototypeOf');
source = removeSupportOwnLast(source);
}
if (isRemoved(source, 'keys')) {
@@ -3326,11 +3362,6 @@
].join('\n' + indent);
});
}
if (isRemoved(source, 'parseInt')) {
source = removeVar(source, 'nativeParseInt');
source = removeVar(source, 'reLeadingSpacesAndZeros');
source = removeVar(source, 'whitespace');
}
if (isRemoved(source, 'sortBy')) {
_.each([removeFromGetObject, removeFromReleaseObject], function(func) {
source = func(source, 'criteria');
@@ -3391,8 +3422,6 @@
source = removeFunction(source, 'slice');
}
if (!/^ *support\.(?:enumErrorProps|nonEnumShadows) *=/m.test(source)) {
source = removeVar(source, 'Error');
source = removeVar(source, 'errorProto');
source = removeFromCreateIterator(source, 'errorClass');
source = removeFromCreateIterator(source, 'errorProto');
@@ -3428,6 +3457,26 @@
? body.replace(RegExp('^' + indent, 'gm'), indent.slice(0, -2))
: match.replace(setup, modified);
});
// remove unused variables
(function() {
var varMap = {},
varNames = getVars(source);
while (varNames.length) {
varNames = _.sortBy(varNames, function(varName) {
var count = getRefCount(source, varName);
varMap[varName] = count;
return count;
});
var varName = varNames[0];
if (varMap[varName] < 2) {
source = removeVar(source, varName);
}
varNames.shift();
}
}());
}
if (_.size(source.match(/\bfreeModule\b/g)) < 2) {
source = removeVar(source, 'freeModule');