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Mini Shell
Mini Shell
const {Parser: AcornParser, isNewLine: acornIsNewLine, getLineInfo: acornGetLineInfo} = require('acorn');
const {full: acornWalkFull} = require('acorn-walk');
const INTERNAL_STATE_NAME = 'VM2_INTERNAL_STATE_DO_NOT_USE_OR_PROGRAM_WILL_FAIL';
function assertType(node, type) {
if (!node) throw new Error(`None existent node expected '${type}'`);
if (node.type !== type) throw new Error(`Invalid node type '${node.type}' expected '${type}'`);
return node;
}
function makeNiceSyntaxError(message, code, filename, location, tokenizer) {
const loc = acornGetLineInfo(code, location);
let end = location;
while (end < code.length && !acornIsNewLine(code.charCodeAt(end))) {
end++;
}
let markerEnd = tokenizer.start === location ? tokenizer.end : location + 1;
if (!markerEnd || markerEnd > end) markerEnd = end;
let markerLen = markerEnd - location;
if (markerLen <= 0) markerLen = 1;
if (message === 'Unexpected token') {
const type = tokenizer.type;
if (type.label === 'name' || type.label === 'privateId') {
message = 'Unexpected identifier';
} else if (type.label === 'eof') {
message = 'Unexpected end of input';
} else if (type.label === 'num') {
message = 'Unexpected number';
} else if (type.label === 'string') {
message = 'Unexpected string';
} else if (type.label === 'regexp') {
message = 'Unexpected token \'/\'';
markerLen = 1;
} else {
const token = tokenizer.value || type.label;
message = `Unexpected token '${token}'`;
}
}
const error = new SyntaxError(message);
if (!filename) return error;
const line = code.slice(location - loc.column, end);
const marker = line.slice(0, loc.column).replace(/\S/g, ' ') + '^'.repeat(markerLen);
error.stack = `${filename}:${loc.line}\n${line}\n${marker}\n\n${error.stack}`;
return error;
}
function transformer(args, body, isAsync, isGenerator, filename) {
let code;
let argsOffset;
if (args === null) {
code = body;
// Note: Keywords are not allows to contain u escapes
if (!/\b(?:catch|import|async)\b/.test(code)) {
return {__proto__: null, code, hasAsync: false};
}
} else {
code = isAsync ? '(async function' : '(function';
if (isGenerator) code += '*';
code += ' anonymous(';
code += args;
argsOffset = code.length;
code += '\n) {\n';
code += body;
code += '\n})';
}
const parser = new AcornParser({
__proto__: null,
ecmaVersion: 2022,
allowAwaitOutsideFunction: args === null && isAsync,
allowReturnOutsideFunction: args === null
}, code);
let ast;
try {
ast = parser.parse();
} catch (e) {
// Try to generate a nicer error message.
if (e instanceof SyntaxError && e.pos !== undefined) {
let message = e.message;
const match = message.match(/^(.*) \(\d+:\d+\)$/);
if (match) message = match[1];
e = makeNiceSyntaxError(message, code, filename, e.pos, parser);
}
throw e;
}
if (args !== null) {
const pBody = assertType(ast, 'Program').body;
if (pBody.length !== 1) throw new SyntaxError('Single function literal required');
const expr = pBody[0];
if (expr.type !== 'ExpressionStatement') throw new SyntaxError('Single function literal required');
const func = expr.expression;
if (func.type !== 'FunctionExpression') throw new SyntaxError('Single function literal required');
if (func.body.start !== argsOffset + 3) throw new SyntaxError('Unexpected end of arg string');
}
const insertions = [];
let hasAsync = false;
const TO_LEFT = -100;
const TO_RIGHT = 100;
let internStateValiable = undefined;
acornWalkFull(ast, (node, state, type) => {
if (type === 'Function') {
if (node.async) hasAsync = true;
}
const nodeType = node.type;
if (nodeType === 'CatchClause') {
const param = node.param;
if (param) {
const name = assertType(param, 'Identifier').name;
const cBody = assertType(node.body, 'BlockStatement');
if (cBody.body.length > 0) {
insertions.push({
__proto__: null,
pos: cBody.body[0].start,
order: TO_LEFT,
code: `${name}=${INTERNAL_STATE_NAME}.handleException(${name});`
});
}
}
} else if (nodeType === 'WithStatement') {
insertions.push({
__proto__: null,
pos: node.object.start,
order: TO_LEFT,
code: INTERNAL_STATE_NAME + '.wrapWith('
});
insertions.push({
__proto__: null,
pos: node.object.end,
order: TO_RIGHT,
code: ')'
});
} else if (nodeType === 'Identifier') {
if (node.name === INTERNAL_STATE_NAME) {
if (internStateValiable === undefined || internStateValiable.start > node.start) {
internStateValiable = node;
}
}
} else if (nodeType === 'ImportExpression') {
insertions.push({
__proto__: null,
pos: node.start,
order: TO_RIGHT,
code: INTERNAL_STATE_NAME + '.'
});
}
});
if (internStateValiable) {
throw makeNiceSyntaxError('Use of internal vm2 state variable', code, filename, internStateValiable.start, {
__proto__: null,
start: internStateValiable.start,
end: internStateValiable.end
});
}
if (insertions.length === 0) return {__proto__: null, code, hasAsync};
insertions.sort((a, b) => (a.pos == b.pos ? a.order - b.order : a.pos - b.pos));
let ncode = '';
let curr = 0;
for (let i = 0; i < insertions.length; i++) {
const change = insertions[i];
ncode += code.substring(curr, change.pos) + change.code;
curr = change.pos;
}
ncode += code.substring(curr);
return {__proto__: null, code: ncode, hasAsync};
}
exports.INTERNAL_STATE_NAME = INTERNAL_STATE_NAME;
exports.transformer = transformer;
Zerion Mini Shell 1.0