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/**
* @fileoverview Add environment defaults to SpiderMonkey's self-hosted JS.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
*/
"use strict";
const path = require("path");
const fs = require("fs");
let gRootDir = null;
// Copied from `tools/lint/eslint/eslint-plugin-mozilla/lib/helpers.js`.
function getRootDir() {
if (!gRootDir) {
function searchUpForIgnore(dirName, filename) {
let parsed = path.parse(dirName);
while (parsed.root !== dirName) {
if (fs.existsSync(path.join(dirName, filename))) {
return dirName;
}
// Move up a level
dirName = parsed.dir;
parsed = path.parse(dirName);
}
return null;
}
let possibleRoot = searchUpForIgnore(
path.dirname(module.filename),
".eslintignore"
);
if (!possibleRoot) {
possibleRoot = searchUpForIgnore(path.resolve(), ".eslintignore");
}
if (!possibleRoot) {
possibleRoot = searchUpForIgnore(path.resolve(), "package.json");
}
if (!possibleRoot) {
// We've couldn't find a root from the module or CWD, so lets just go
// for the CWD. We really don't want to throw if possible, as that
// tends to give confusing results when used with ESLint.
possibleRoot = process.cwd();
}
gRootDir = possibleRoot;
}
return gRootDir;
}
function tryReadFile(filePath) {
let absPath = path.join(getRootDir(), filePath);
if (!fs.existsSync(absPath)) {
// Safely handle the case when the file wasn't found, because throwing
// errors can lead to confusing result when used with ESLint.
return "";
}
return fs.readFileSync(absPath, "utf-8");
}
// Search for top-level declarations, #defines, and #includes.
function addGlobalsFrom(dirName, fileName, globals) {
let filePath = path.join(dirName, fileName);
// Definitions are separated by line.
let lines = tryReadFile(filePath).split("\n");
// We don't have to fully parse the source code, because it's formatted
// through "prettier", which means we know the exact code structure.
//
// |class| is disallowed in self-hosted code, so we don't have to handle it.
for (let line of lines) {
if (
line.startsWith("function") ||
line.startsWith("function*") ||
line.startsWith("async function") ||
line.startsWith("async function*")
) {
let m = line.match(/^(?:async )?function(?:\*)?\s+([\w\$]+)\s*\(/);
if (m) {
globals[m[1]] = "readonly";
}
} else if (
line.startsWith("var") ||
line.startsWith("let") ||
line.startsWith("const")
) {
let m = line.match(/^(?:var|let|const)\s+([\w\$]+)\s*[;=]/);
if (m) {
globals[m[1]] = "readonly";
}
} else if (line.startsWith("#define")) {
let m = line.match(/^#define (\w+)/);
if (m) {
globals[m[1]] = "readonly";
}
} else if (line.startsWith("#include")) {
let m = line.match(/^#include \"([\w\.]+)\"$/);
if (m) {
// Also process definitions from includes.
addGlobalsFrom(dirName, m[1], globals);
}
}
}
}
function selfHostingDefines(dirName = "js/src/builtin/") {
let absDir = path.join(getRootDir(), dirName);
if (!fs.existsSync(absDir)) {
// See |tryReadFile| for why we avoid to throw any errors.
return {};
}
// Search sub-directories and js-files within |dirName|.
let dirs = [];
let jsFiles = [];
for (let name of fs.readdirSync(absDir)) {
let stat = fs.statSync(path.join(absDir, name));
if (stat.isDirectory()) {
dirs.push(name);
} else if (stat.isFile() && name.endsWith(".js")) {
jsFiles.push(name);
}
}
let globals = Object.create(null);
// Process each js-file.
for (let jsFile of jsFiles) {
addGlobalsFrom(dirName, jsFile, globals);
}
// Recursively traverse all sub-directories.
for (let dir of dirs) {
globals = { ...globals, ...selfHostingDefines(path.join(dirName, dir)) };
}
return globals;
}
function selfHostingFunctions() {
// Definitions can be spread across multiple lines and may have extra
// whitespace, so we simply remove all whitespace and match over the complete
// file.
let content = tryReadFile("js/src/vm/SelfHosting.cpp").replace(/\s+/g, "");
let globals = Object.create(null);
let re = /(?:JS_FN|JS_INLINABLE_FN|JS_TRAMPOLINE_FN)\("(\w+)"/g;
for (let m of content.matchAll(re)) {
globals[m[1]] = "readonly";
}
return globals;
}
function errorNumbers() {
// Definitions are separated by line.
let lines = tryReadFile("js/public/friend/ErrorNumbers.msg").split("\n");
let globals = Object.create(null);
for (let line of lines) {
let m = line.match(/^MSG_DEF\((\w+),/);
if (m) {
globals[m[1]] = "readonly";
}
}
return globals;
}
const globals = {
...selfHostingDefines(),
...selfHostingFunctions(),
...errorNumbers(),
};
module.exports = {
globals,
};