hyperledger-solang_solang

solang - Solidity Compiler for Solana, Substrate, and ewasm

Welcome to Solang, a new Solidity compiler written in rust which uses llvm as the compiler backend. Solang can compile Solidity for Solana, Substrate, and ewasm. Solang is source compatible with Solidity 0.7, with some caveats due to differences in the underlying blockchain.

Solang is under active development right now, and has extensive documentation.

Simple example

First build Solang or use the container, then write the following to flipper.sol:

contract flipper {
	bool private value;

	constructor(bool initvalue) public {
		value = initvalue;
	}

	function flip() public {
		value = !value;
	}

	function get() public view returns (bool) {
		return value;
	}
}

Build for Solana

Run:

solang --target solana flipper.sol

Alternatively if you want to use the solang container, run:

docker run --rm -it -v $(pwd):/sources ghcr.io/hyperledger-labs/solang -v -o /sources --target solana /sources/flipper.sol

A file called flipper.abi and bundle.so. Now install @solana/solidity:

npm install @solana/solidity

Save the following to flipper.js:

const { Connection, LAMPORTS_PER_SOL, Keypair } = require('@solana/web3.js');
const { Contract, Program } = require('@solana/solidity');
const { readFileSync } = require('fs');

const FLIPPER_ABI = JSON.parse(readFileSync('./flipper.abi', 'utf8'));
const PROGRAM_SO = readFileSync('./bundle.so');

(async function () {
    console.log('Connecting to your local Solana node ...');
    const connection = new Connection('http://localhost:8899', 'confirmed');

    const payer = Keypair.generate();

    console.log('Airdropping SOL to a new wallet ...');
    const signature = await connection.requestAirdrop(payer.publicKey, LAMPORTS_PER_SOL);
    await connection.confirmTransaction(signature, 'confirmed');

    const program = Keypair.generate();
    const storage = Keypair.generate();

    const contract = new Contract(connection, program.publicKey, storage.publicKey, FLIPPER_ABI, payer);

    await contract.load(program, PROGRAM_SO);

    console.log('Program deployment finished, deploying the flipper contract ...');

    await contract.deploy('flipper', [true], program, storage, 17);

    const res = await contract.functions.get();
    console.log('state: ' + res.result);

    await contract.functions.flip();

    const res2 = await contract.functions.get();
    console.log('state: ' + res2.result);
})();

And now run:

node flipper.js

Build for Substrate

Run:

solang --target substrate flipper.sol

Alternatively if you want to use the solang container, run:

docker run --rm -it -v $(pwd):/sources ghcr.io/hyperledger-labs/solang -v -o /sources --target substrate /sources/flipper.sol

You will have a file called flipper.contract. You can use this directly in the Polkadot UI, as if your smart contract was written using ink!.

Tentative roadmap

Solang has a high level of compatibility with many blockchains. We are trying to ensure the compiler stays up to date with the newest Solidity syntax and features. In addition, we focus on bringing new performance optimizations and improve developer experience. Here is a brief description of what we envision for the next versions.

V0.2

Milestone	Status
Specify values as "1 sol" and "1e9 lamports"	In progress
Solana SPL tokens compatibility	In progress

V0.3

Milestone	Status
Call Rust contracts from Solidity	Not started
Parse and resolve inline assembly	Completed
Improvements in overflow checking	Not started

V0.4

Milestone	Status
Call Solidity from Rust	Not started
Generate code for inline assembly	Not started
Improve management over optimization passes	Not Started
Dead code elimination	Not started
ewasm target	Not started

License

Apache 2.0