Parses the latest hermes operands into a json format file.

hermes.ts

import fetch from 'node-fetch'

interface GroupedRegExpMatchArray extends RegExpMatchArray {
    groups?: {
        define: string,
        name: string,
        options?: string
    }
}

interface StringRegExpMatchArray extends RegExpMatchArray {
    groups?: {
        name: string,
        index: string
    }
}

(async () => {
    const url = 'https://raw.githubusercontent.com/facebook/hermes/main/include/hermes/BCGen/HBC/BytecodeList.def';

    const latestOpcodes = await fetch(url).then(async (o) => {
        return await o.text()
    })

    const lines = latestOpcodes.split('\n')
    const regex = new RegExp(/^DEFINE_(?<define>(OPCODE|JUMP)_\d)\((?<name>[A-Za-z0-9]+)(?<options>(, [A-Za-z0-9]+)+?)?\)/);
    const stringRegex = new RegExp(/OPERAND_STRING_ID\((?<name>[A-Za-z0-9]+), (?<index>\d+)\)/);

    const resultingObjects: {[name: string]: Array<string>} = {}

    function handleLine(line: string) {
        const result: GroupedRegExpMatchArray | null = line.match(regex) as any;

        if (!result) {
            return;
        }

        if (resultingObjects[result.groups.name]) {
            console.log('Already registered ', result.groups.name)
        } else {
            let options = result.groups.options ? result.groups.options.substring(2) : '';

            switch (result.groups.define) {
                case 'JUMP_1': {
                    handleLine(`DEFINE_OPCODE_1(${result.groups.name}, Addr8)`);
                    handleLine(`DEFINE_OPCODE_1(${result.groups.name}Long, Addr32)`);

                    return;
                }
                case 'JUMP_2': {
                    handleLine(`DEFINE_OPCODE_2(${result.groups.name}, Addr8, Reg8)`);
                    handleLine(`DEFINE_OPCODE_2(${result.groups.name}Long, Addr32, Reg8)`);

                    return;
                }
                case 'JUMP_3': {
                    handleLine(`DEFINE_OPCODE_3(${result.groups.name}, Addr8, Reg8, Reg8)`);
                    handleLine(`DEFINE_OPCODE_3(${result.groups.name}Long, Addr32, Reg8, Reg8)`);

                    return;
                }
            }

            let array: Array<string> = [];

            if (options.indexOf(', ') >= 0) {
                array.push(...options.split(', '))
            } else if (options.trim().length > 0) {
                array.push(options)
            }

            resultingObjects[result.groups.name] = array;

            return result.groups.name
        }
    }

    function handleStringInjection(line: string) {
        const result: StringRegExpMatchArray | null = line.match(stringRegex) as any;

        if (!result) {
            console.error('Unhandled string line ' + line)

            return;
        }

        let arr = resultingObjects[result.groups.name];

        arr[parseInt(result.groups.index) - 1] += ':S'

        resultingObjects[result.groups.name] = arr;
    }

    for (let i = 0; i < lines.length; i++) {
        const line = lines[i];

        if (line.indexOf('OPERAND_STRING_ID') >= 0) {
            handleStringInjection(line)
        } else {
            handleLine(line);
        }
    }

    console.log(JSON.stringify(resultingObjects, null, 4))
    console.log(`Ended up with ${Object.keys(resultingObjects).length} keys.`)
})();