Prototyping canonical SolanaTBTC token with the Solang compiler

cross-chain/solana/.gitignore

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+*.js
+*.so
+*.key
+*.json
+!tsconfig.json
+!package.json
+node_modules
+yarn.lock
+/test-ledger

cross-chain/solana/README.adoc

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+:toc: macro
+
+= Threshold cross-chain - Solana
+
+This package brings Bitcoin to Solana. For more details please
+see link:https://github.com/keep-network/tbtc-v2/blob/main/docs/rfc/rfc-8.adoc[RFC 8: Cross-chain Tokenized Threshold BTC]
+
+== How it works?
+
+```
++----------------------------+ +-----------------------------------------------------------------------+
+| Ethereum | | Solana |
+| | | |
+| +----------------------+ | | +----------------------+ +-----------------------+ +------------+ |
+| | Wormhole TokenBridge |--|---------|--| Wormhole TokenBridge |--| SolanaWormholeGateway |--| SolanaTBTC | |
+| +----------------------+ | | +----------------------+ +-----------------------+ +------------+ |
+| | | |
++----------------------------+ +-----------------------------------------------------------------------+
+```
+
+- `SolanaTBTC` canonical tBTC token on Solana with a minting authority
+delegated to `SolanaWormholeGateway`.
+- `SolanaWormholeGateway` is a smart contract wrapping and unwrapping 
+Wormhole-specific tBTC representation into the canonical `SolanaTBTC` token.
+
+=== Local development
+
+For testing and debugging purposes it is convinient to run Solana cluster locally.
+
+link:https://docs.solana.com/cli/install-solana-cli-tools#use-solanas-install-tool[Install] Solana Tool Suite
+
+In terminal run `solana-test-validator`. For more details see link:https://docs.solana.com/developing/test-validator[Solana Test Validator]
+
+==== Running tests
+
+Navigate to `/cross-chain/solana` and run `runTests.sh`. This script compiles Solidity contract(s) to produce Solana artifacts.
+
+=== Updating Wormhole Gateway mapping
+
+TODO: add
+
+=== Deploy contracts
+
+TODO: add
+
+=== Contract upgrades
+
+Supported out of the box. See https://docs.solana.com/cli/deploy-a-program#redeploy-a-program
+
+TODO: add examples
+
+=== Freezing and thawing token account
+
+Supported with a freezing authority passed as an argument during token creation.
+
+TODO: add examples

cross-chain/solana/SolanaTBTC.sol

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+import './solana-library/spl_token.sol';
+import 'solana';
+
+contract SolanaTBTC {
+ /// @notice Indicates if the given address is a minter. Only minters can
+ /// mint the token.
+ mapping(address => bool) isMinter;
+
+ /// @notice List of all minters.
+ address[] minters;
+
+ /// @notice owner
+ address authority;
+
+ /// @notice mint account
+ /// @dev Stores information about the token itself. E.g. current supply and 
+ /// its authorities
+ address mint;
+
+ event MinterAdded(address minter);
+ event MinterRemoved(address minter);
+
+ modifier needs_authority() {
+ for (uint64 i = 0; i < tx.accounts.length; i++) {
+ AccountInfo ai = tx.accounts[i];
+ if (ai.key == authority && ai.is_signer) {
+ _;
+ return;
+ }
+ }
+
+ print("Not signed by authority");
+ revert("Not signed by authority");
+ }
+
+ modifier minter_only() {
+ for (uint64 i = 0; i < tx.accounts.length; i++) {
+ AccountInfo ai = tx.accounts[i];
+ print("checking if a minter");
+ if (isMinter[ai.key] && ai.is_signer) {
+ _;
+ return;
+ }
+ }
+
+ print("Not a minter");
+ revert("Not a minter");
+ }
+
+ constructor(address initial_authority) {
+ authority = initial_authority;
+ }
+
+ /// @notice Adds the address to the minters list.
+ /// @dev Requirements:
+ /// - The caller must have authority.
+ /// - `minter` must not be a minter address already.
+ /// @param minter The address to be added as a minter. This address can mint
+ /// SolanaTBTC token.
+ function add_minter(address minter) needs_authority public {
+ print("adding a minter...");
+ require(!isMinter[minter], "This address is already a minter");
+ isMinter[minter] = true;
+ minters.push(minter);
+ emit MinterAdded(minter);
+ print("added a minter...");
+ }
+
+ /// @notice Removes the address from the minters list.
+ /// @dev Requirements:
+ /// - The caller must have authority.
+ /// - `minter` must be a minter address.
+ /// @param minter The address to be removed from the minters list.
+ function remove_minter(address minter) public needs_authority {
+ require(isMinter[minter], "This address is not a minter");
+ delete isMinter[minter];
+
+ // We do not expect too many minters so a simple loop is safe.
+ for (uint256 i = 0; i < minters.length; i++) {
+ if (minters[i] == minter) {
+ minters[i] = minters[minters.length - 1];
+ minters.pop();
+ break;
+ }
+ }
+
+ emit MinterRemoved(minter);
+ }
+
+ function set_mint(address _mint) needs_authority public {
+ mint = _mint;
+ }
+
+ function mint_to(address account, address _authority, uint64 amount) minter_only public {
+ print("yo, I'm in mint_to");
+ SplToken.mint_to(mint, account, _authority, amount);
+ }
+
+ function total_supply() public view returns (uint64) {
+ return SplToken.total_supply(mint);
+ }
+
+ function get_balance(address account) public view returns (uint64) {
+ return SplToken.get_balance(account);
+ }
+
+ function transfer(address from, address to, address owner, uint64 amount) public {
+ SplToken.transfer(from, to, owner, amount);
+ }
+
+ function burn(address account, address owner, uint64 amount) public {
+ SplToken.burn(account, mint, owner, amount);
+ }
+
+ /// @notice Allows to fetch a list of all minters.
+ function get_minters() public view returns (address[] memory) {
+ return minters;
+ }
+}