517 lines
16 KiB
JavaScript
517 lines
16 KiB
JavaScript
|
/***********************************************************************
|
||
|
|
|
||
|
|
A JavaScript tokenizer / parser / beautifier / compressor.
|
||
|
|
https://github.com/mishoo/UglifyJS2
|
||
|
|
|
||
|
|
-------------------------------- (C) ---------------------------------
|
||
|
|
|
||
|
|
Author: Mihai Bazon
|
||
|
|
<mihai.bazon@gmail.com>
|
||
|
|
http://mihai.bazon.net/blog
|
||
|
|
|
||
|
|
Distributed under the BSD license:
|
||
|
|
|
||
|
|
Copyright 2012 (c) Mihai Bazon <mihai.bazon@gmail.com>
|
||
|
|
|
||
|
|
Redistribution and use in source and binary forms, with or without
|
||
|
|
modification, are permitted provided that the following conditions
|
||
|
|
are met:
|
||
|
|
|
||
|
|
* Redistributions of source code must retain the above
|
||
|
|
copyright notice, this list of conditions and the following
|
||
|
|
disclaimer.
|
||
|
|
|
||
|
|
* Redistributions in binary form must reproduce the above
|
||
|
|
copyright notice, this list of conditions and the following
|
||
|
|
disclaimer in the documentation and/or other materials
|
||
|
|
provided with the distribution.
|
||
|
|
|
||
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
|
||
|
|
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||
|
|
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
|
||
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
|
||
|
|
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
||
|
|
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
||
|
|
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
||
|
|
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
|
||
|
|
TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
|
||
|
|
THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||
|
|
SUCH DAMAGE.
|
||
|
|
|
||
|
|
***********************************************************************/
|
||
|
|
|
||
|
|
import {
|
||
|
|
HOP,
|
||
|
|
makePredicate,
|
||
|
|
return_this,
|
||
|
|
string_template,
|
||
|
|
regexp_source_fix,
|
||
|
|
regexp_is_safe,
|
||
|
|
} from "../utils/index.js";
|
||
|
|
import {
|
||
|
|
AST_Array,
|
||
|
|
AST_BigInt,
|
||
|
|
AST_Binary,
|
||
|
|
AST_Call,
|
||
|
|
AST_Chain,
|
||
|
|
AST_Class,
|
||
|
|
AST_Conditional,
|
||
|
|
AST_Constant,
|
||
|
|
AST_Dot,
|
||
|
|
AST_Expansion,
|
||
|
|
AST_Function,
|
||
|
|
AST_Lambda,
|
||
|
|
AST_New,
|
||
|
|
AST_Node,
|
||
|
|
AST_Object,
|
||
|
|
AST_PropAccess,
|
||
|
|
AST_RegExp,
|
||
|
|
AST_Statement,
|
||
|
|
AST_Symbol,
|
||
|
|
AST_SymbolRef,
|
||
|
|
AST_TemplateString,
|
||
|
|
AST_UnaryPrefix,
|
||
|
|
AST_With,
|
||
|
|
} from "../ast.js";
|
||
|
|
import { is_undeclared_ref} from "./inference.js";
|
||
|
|
import { is_pure_native_value, is_pure_native_fn, is_pure_native_method } from "./native-objects.js";
|
||
|
|
|
||
|
|
// methods to evaluate a constant expression
|
||
|
|
|
||
|
|
function def_eval(node, func) {
|
||
|
|
node.DEFMETHOD("_eval", func);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Used to propagate a nullish short-circuit signal upwards through the chain.
|
||
|
|
export const nullish = Symbol("This AST_Chain is nullish");
|
||
|
|
|
||
|
|
// If the node has been successfully reduced to a constant,
|
||
|
|
// then its value is returned; otherwise the element itself
|
||
|
|
// is returned.
|
||
|
|
// They can be distinguished as constant value is never a
|
||
|
|
// descendant of AST_Node.
|
||
|
|
AST_Node.DEFMETHOD("evaluate", function (compressor) {
|
||
|
|
if (!compressor.option("evaluate"))
|
||
|
|
return this;
|
||
|
|
var val = this._eval(compressor, 1);
|
||
|
|
if (!val || val instanceof RegExp)
|
||
|
|
return val;
|
||
|
|
if (typeof val == "function" || typeof val == "object" || val == nullish)
|
||
|
|
return this;
|
||
|
|
|
||
|
|
// Evaluated strings can be larger than the original expression
|
||
|
|
if (typeof val === "string") {
|
||
|
|
const unevaluated_size = this.size(compressor);
|
||
|
|
if (val.length + 2 > unevaluated_size) return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
return val;
|
||
|
|
});
|
||
|
|
|
||
|
|
var unaryPrefix = makePredicate("! ~ - + void");
|
||
|
|
AST_Node.DEFMETHOD("is_constant", function () {
|
||
|
|
// Accomodate when compress option evaluate=false
|
||
|
|
// as well as the common constant expressions !0 and -1
|
||
|
|
if (this instanceof AST_Constant) {
|
||
|
|
return !(this instanceof AST_RegExp);
|
||
|
|
} else {
|
||
|
|
return this instanceof AST_UnaryPrefix
|
||
|
|
&& this.expression instanceof AST_Constant
|
||
|
|
&& unaryPrefix.has(this.operator);
|
||
|
|
}
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Statement, function () {
|
||
|
|
throw new Error(string_template("Cannot evaluate a statement [{file}:{line},{col}]", this.start));
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Lambda, return_this);
|
||
|
|
def_eval(AST_Class, return_this);
|
||
|
|
def_eval(AST_Node, return_this);
|
||
|
|
def_eval(AST_Constant, function () {
|
||
|
|
return this.getValue();
|
||
|
|
});
|
||
|
|
|
||
|
|
const supports_bigint = typeof BigInt === "function";
|
||
|
|
def_eval(AST_BigInt, function () {
|
||
|
|
if (supports_bigint) {
|
||
|
|
return BigInt(this.value);
|
||
|
|
} else {
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_RegExp, function (compressor) {
|
||
|
|
let evaluated = compressor.evaluated_regexps.get(this.value);
|
||
|
|
if (evaluated === undefined && regexp_is_safe(this.value.source)) {
|
||
|
|
try {
|
||
|
|
const { source, flags } = this.value;
|
||
|
|
evaluated = new RegExp(source, flags);
|
||
|
|
} catch (e) {
|
||
|
|
evaluated = null;
|
||
|
|
}
|
||
|
|
compressor.evaluated_regexps.set(this.value, evaluated);
|
||
|
|
}
|
||
|
|
return evaluated || this;
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_TemplateString, function () {
|
||
|
|
if (this.segments.length !== 1) return this;
|
||
|
|
return this.segments[0].value;
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Function, function (compressor) {
|
||
|
|
if (compressor.option("unsafe")) {
|
||
|
|
var fn = function () { };
|
||
|
|
fn.node = this;
|
||
|
|
fn.toString = () => this.print_to_string();
|
||
|
|
return fn;
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Array, function (compressor, depth) {
|
||
|
|
if (compressor.option("unsafe")) {
|
||
|
|
var elements = [];
|
||
|
|
for (var i = 0, len = this.elements.length; i < len; i++) {
|
||
|
|
var element = this.elements[i];
|
||
|
|
var value = element._eval(compressor, depth);
|
||
|
|
if (element === value)
|
||
|
|
return this;
|
||
|
|
elements.push(value);
|
||
|
|
}
|
||
|
|
return elements;
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Object, function (compressor, depth) {
|
||
|
|
if (compressor.option("unsafe")) {
|
||
|
|
var val = {};
|
||
|
|
for (var i = 0, len = this.properties.length; i < len; i++) {
|
||
|
|
var prop = this.properties[i];
|
||
|
|
if (prop instanceof AST_Expansion)
|
||
|
|
return this;
|
||
|
|
var key = prop.key;
|
||
|
|
if (key instanceof AST_Symbol) {
|
||
|
|
key = key.name;
|
||
|
|
} else if (key instanceof AST_Node) {
|
||
|
|
key = key._eval(compressor, depth);
|
||
|
|
if (key === prop.key)
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
if (typeof Object.prototype[key] === "function") {
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
if (prop.value instanceof AST_Function)
|
||
|
|
continue;
|
||
|
|
val[key] = prop.value._eval(compressor, depth);
|
||
|
|
if (val[key] === prop.value)
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
return val;
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
});
|
||
|
|
|
||
|
|
var non_converting_unary = makePredicate("! typeof void");
|
||
|
|
def_eval(AST_UnaryPrefix, function (compressor, depth) {
|
||
|
|
var e = this.expression;
|
||
|
|
if (compressor.option("typeofs")
|
||
|
|
&& this.operator == "typeof") {
|
||
|
|
// Function would be evaluated to an array and so typeof would
|
||
|
|
// incorrectly return 'object'. Hence making is a special case.
|
||
|
|
if (e instanceof AST_Lambda
|
||
|
|
|| e instanceof AST_SymbolRef
|
||
|
|
&& e.fixed_value() instanceof AST_Lambda) {
|
||
|
|
return typeof function () { };
|
||
|
|
}
|
||
|
|
if (
|
||
|
|
(e instanceof AST_Object
|
||
|
|
|| e instanceof AST_Array
|
||
|
|
|| (e instanceof AST_SymbolRef
|
||
|
|
&& (e.fixed_value() instanceof AST_Object
|
||
|
|
|| e.fixed_value() instanceof AST_Array)))
|
||
|
|
&& !e.has_side_effects(compressor)
|
||
|
|
) {
|
||
|
|
return typeof {};
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (!non_converting_unary.has(this.operator))
|
||
|
|
depth++;
|
||
|
|
e = e._eval(compressor, depth);
|
||
|
|
if (e === this.expression)
|
||
|
|
return this;
|
||
|
|
switch (this.operator) {
|
||
|
|
case "!": return !e;
|
||
|
|
case "typeof":
|
||
|
|
// typeof <RegExp> returns "object" or "function" on different platforms
|
||
|
|
// so cannot evaluate reliably
|
||
|
|
if (e instanceof RegExp)
|
||
|
|
return this;
|
||
|
|
return typeof e;
|
||
|
|
case "void": return void e;
|
||
|
|
case "~": return ~e;
|
||
|
|
case "-": return -e;
|
||
|
|
case "+": return +e;
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
});
|
||
|
|
|
||
|
|
var non_converting_binary = makePredicate("&& || ?? === !==");
|
||
|
|
const identity_comparison = makePredicate("== != === !==");
|
||
|
|
const has_identity = value => typeof value === "object"
|
||
|
|
|| typeof value === "function"
|
||
|
|
|| typeof value === "symbol";
|
||
|
|
|
||
|
|
def_eval(AST_Binary, function (compressor, depth) {
|
||
|
|
if (!non_converting_binary.has(this.operator))
|
||
|
|
depth++;
|
||
|
|
|
||
|
|
var left = this.left._eval(compressor, depth);
|
||
|
|
if (left === this.left)
|
||
|
|
return this;
|
||
|
|
var right = this.right._eval(compressor, depth);
|
||
|
|
if (right === this.right)
|
||
|
|
return this;
|
||
|
|
|
||
|
|
if (left != null
|
||
|
|
&& right != null
|
||
|
|
&& identity_comparison.has(this.operator)
|
||
|
|
&& has_identity(left)
|
||
|
|
&& has_identity(right)
|
||
|
|
&& typeof left === typeof right) {
|
||
|
|
// Do not compare by reference
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Do not mix BigInt and Number; Don't use `>>>` on BigInt or `/ 0n`
|
||
|
|
if (
|
||
|
|
(typeof left === "bigint") !== (typeof right === "bigint")
|
||
|
|
|| typeof left === "bigint"
|
||
|
|
&& (this.operator === ">>>"
|
||
|
|
|| this.operator === "/" && Number(right) === 0)
|
||
|
|
) {
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
var result;
|
||
|
|
switch (this.operator) {
|
||
|
|
case "&&": result = left && right; break;
|
||
|
|
case "||": result = left || right; break;
|
||
|
|
case "??": result = left != null ? left : right; break;
|
||
|
|
case "|": result = left | right; break;
|
||
|
|
case "&": result = left & right; break;
|
||
|
|
case "^": result = left ^ right; break;
|
||
|
|
case "+": result = left + right; break;
|
||
|
|
case "*": result = left * right; break;
|
||
|
|
case "**": result = left ** right; break;
|
||
|
|
case "/": result = left / right; break;
|
||
|
|
case "%": result = left % right; break;
|
||
|
|
case "-": result = left - right; break;
|
||
|
|
case "<<": result = left << right; break;
|
||
|
|
case ">>": result = left >> right; break;
|
||
|
|
case ">>>": result = left >>> right; break;
|
||
|
|
case "==": result = left == right; break;
|
||
|
|
case "===": result = left === right; break;
|
||
|
|
case "!=": result = left != right; break;
|
||
|
|
case "!==": result = left !== right; break;
|
||
|
|
case "<": result = left < right; break;
|
||
|
|
case "<=": result = left <= right; break;
|
||
|
|
case ">": result = left > right; break;
|
||
|
|
case ">=": result = left >= right; break;
|
||
|
|
default:
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
if (typeof result === "number" && isNaN(result) && compressor.find_parent(AST_With)) {
|
||
|
|
// leave original expression as is
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
return result;
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Conditional, function (compressor, depth) {
|
||
|
|
var condition = this.condition._eval(compressor, depth);
|
||
|
|
if (condition === this.condition)
|
||
|
|
return this;
|
||
|
|
var node = condition ? this.consequent : this.alternative;
|
||
|
|
var value = node._eval(compressor, depth);
|
||
|
|
return value === node ? this : value;
|
||
|
|
});
|
||
|
|
|
||
|
|
// Set of AST_SymbolRef which are currently being evaluated.
|
||
|
|
// Avoids infinite recursion of ._eval()
|
||
|
|
const reentrant_ref_eval = new Set();
|
||
|
|
def_eval(AST_SymbolRef, function (compressor, depth) {
|
||
|
|
if (reentrant_ref_eval.has(this))
|
||
|
|
return this;
|
||
|
|
|
||
|
|
var fixed = this.fixed_value();
|
||
|
|
if (!fixed)
|
||
|
|
return this;
|
||
|
|
|
||
|
|
reentrant_ref_eval.add(this);
|
||
|
|
const value = fixed._eval(compressor, depth);
|
||
|
|
reentrant_ref_eval.delete(this);
|
||
|
|
|
||
|
|
if (value === fixed)
|
||
|
|
return this;
|
||
|
|
|
||
|
|
if (value && typeof value == "object") {
|
||
|
|
var escaped = this.definition().escaped;
|
||
|
|
if (escaped && depth > escaped)
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
return value;
|
||
|
|
});
|
||
|
|
|
||
|
|
const global_objs = { Array, Math, Number, Object, String };
|
||
|
|
|
||
|
|
const regexp_flags = new Set([
|
||
|
|
"dotAll",
|
||
|
|
"global",
|
||
|
|
"ignoreCase",
|
||
|
|
"multiline",
|
||
|
|
"sticky",
|
||
|
|
"unicode",
|
||
|
|
]);
|
||
|
|
|
||
|
|
def_eval(AST_PropAccess, function (compressor, depth) {
|
||
|
|
let obj = this.expression._eval(compressor, depth + 1);
|
||
|
|
if (obj === nullish || (this.optional && obj == null)) return nullish;
|
||
|
|
|
||
|
|
// `.length` of strings and arrays is always safe
|
||
|
|
if (this.property === "length") {
|
||
|
|
if (typeof obj === "string") {
|
||
|
|
return obj.length;
|
||
|
|
}
|
||
|
|
|
||
|
|
const is_spreadless_array =
|
||
|
|
obj instanceof AST_Array
|
||
|
|
&& obj.elements.every(el => !(el instanceof AST_Expansion));
|
||
|
|
|
||
|
|
if (
|
||
|
|
is_spreadless_array
|
||
|
|
&& obj.elements.every(el => !el.has_side_effects(compressor))
|
||
|
|
) {
|
||
|
|
return obj.elements.length;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (compressor.option("unsafe")) {
|
||
|
|
var key = this.property;
|
||
|
|
if (key instanceof AST_Node) {
|
||
|
|
key = key._eval(compressor, depth);
|
||
|
|
if (key === this.property)
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
var exp = this.expression;
|
||
|
|
if (is_undeclared_ref(exp)) {
|
||
|
|
var aa;
|
||
|
|
var first_arg = exp.name === "hasOwnProperty"
|
||
|
|
&& key === "call"
|
||
|
|
&& (aa = compressor.parent() && compressor.parent().args)
|
||
|
|
&& (aa && aa[0]
|
||
|
|
&& aa[0].evaluate(compressor));
|
||
|
|
|
||
|
|
first_arg = first_arg instanceof AST_Dot ? first_arg.expression : first_arg;
|
||
|
|
|
||
|
|
if (first_arg == null || first_arg.thedef && first_arg.thedef.undeclared) {
|
||
|
|
return this.clone();
|
||
|
|
}
|
||
|
|
if (!is_pure_native_value(exp.name, key))
|
||
|
|
return this;
|
||
|
|
obj = global_objs[exp.name];
|
||
|
|
} else {
|
||
|
|
if (obj instanceof RegExp) {
|
||
|
|
if (key == "source") {
|
||
|
|
return regexp_source_fix(obj.source);
|
||
|
|
} else if (key == "flags" || regexp_flags.has(key)) {
|
||
|
|
return obj[key];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (!obj || obj === exp || !HOP(obj, key))
|
||
|
|
return this;
|
||
|
|
|
||
|
|
if (typeof obj == "function")
|
||
|
|
switch (key) {
|
||
|
|
case "name":
|
||
|
|
return obj.node.name ? obj.node.name.name : "";
|
||
|
|
case "length":
|
||
|
|
return obj.node.length_property();
|
||
|
|
default:
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return obj[key];
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Chain, function (compressor, depth) {
|
||
|
|
const evaluated = this.expression._eval(compressor, depth);
|
||
|
|
return evaluated === nullish
|
||
|
|
? undefined
|
||
|
|
: evaluated === this.expression
|
||
|
|
? this
|
||
|
|
: evaluated;
|
||
|
|
});
|
||
|
|
|
||
|
|
def_eval(AST_Call, function (compressor, depth) {
|
||
|
|
var exp = this.expression;
|
||
|
|
|
||
|
|
const callee = exp._eval(compressor, depth);
|
||
|
|
if (callee === nullish || (this.optional && callee == null)) return nullish;
|
||
|
|
|
||
|
|
if (compressor.option("unsafe") && exp instanceof AST_PropAccess) {
|
||
|
|
var key = exp.property;
|
||
|
|
if (key instanceof AST_Node) {
|
||
|
|
key = key._eval(compressor, depth);
|
||
|
|
if (key === exp.property)
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
var val;
|
||
|
|
var e = exp.expression;
|
||
|
|
if (is_undeclared_ref(e)) {
|
||
|
|
var first_arg = e.name === "hasOwnProperty" &&
|
||
|
|
key === "call" &&
|
||
|
|
(this.args[0] && this.args[0].evaluate(compressor));
|
||
|
|
|
||
|
|
first_arg = first_arg instanceof AST_Dot ? first_arg.expression : first_arg;
|
||
|
|
|
||
|
|
if ((first_arg == null || first_arg.thedef && first_arg.thedef.undeclared)) {
|
||
|
|
return this.clone();
|
||
|
|
}
|
||
|
|
if (!is_pure_native_fn(e.name, key)) return this;
|
||
|
|
val = global_objs[e.name];
|
||
|
|
} else {
|
||
|
|
val = e._eval(compressor, depth + 1);
|
||
|
|
if (val === e || !val)
|
||
|
|
return this;
|
||
|
|
if (!is_pure_native_method(val.constructor.name, key))
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
var args = [];
|
||
|
|
for (var i = 0, len = this.args.length; i < len; i++) {
|
||
|
|
var arg = this.args[i];
|
||
|
|
var value = arg._eval(compressor, depth);
|
||
|
|
if (arg === value)
|
||
|
|
return this;
|
||
|
|
if (arg instanceof AST_Lambda)
|
||
|
|
return this;
|
||
|
|
args.push(value);
|
||
|
|
}
|
||
|
|
try {
|
||
|
|
return val[key].apply(val, args);
|
||
|
|
} catch (ex) {
|
||
|
|
// We don't really care
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
});
|
||
|
|
|
||
|
|
// Also a subclass of AST_Call
|
||
|
|
def_eval(AST_New, return_this);
|