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 0.8, with some caveats due to differences in the underlying blockchain.

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

Installation

Solang is available as a Brew cask for MacOS, with the following command:

brew install hyperledger-labs/solang/solang

For other operating systems, please check the installation guide.

Simple example

After installing the compiler, 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 compile --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 compile -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], 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

Status

⚠️ Solang was developed against Substrate v3.0. It has been a while since the last time the Substrate target was worked on, which introduced a few known regressions. Currently, the following is known to not work with recent Substrate versions:

• Function call arguments of type address
• Function return values of type address
• Cross-contract calls
• Events with indexed fields

Maintenance on the Substrate target has now resumed and we are working on fixing these issues.

Building

Run:

solang compile --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 Contracts 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
Solana SPL tokens compatibility	Completed
Parse and resolve inline assembly	Completed
Generate code for inline assembly	Completed
Support Solana's Program Derived Addresses	In Progress
Support latest Substrate production target	In Progress

V0.3

Milestone	Status
Call Solana's Rust contracts from Solidity	In progress
Improvements in overflow checking	In progress
Call Solidity from Solana's Rust contracts	Not started
Improve parser resilience	Not started
Improve developer experience for Substrate	Not started
Tooling for calls between ink! <> solidity	Not started

V0.4

Milestone	Status
Improve management over optimization passes	Not started
Specify values as "1 sol" and "1e9 lamports"	In progress
Adopt single static assignment for code generation	Not started
Support openzeppelin on Substrate target	Not started
Provide Solidity -> Substrate porting guide	Not started

License

Apache 2.0