Ahmad Kaouk
|
b5a6406470
|
feat: Add ERC20 Balances precompile (#150)
## Summary
- Introduces an ERC20-compatible precompile backed by `pallet_balances`,
including approvals and EIP-2612 permit.
- Wires the precompile into Mainnet, Testnet, and Stagenet at address
`0x0000000000000000000000000000000000000802` (u64: 2050).
- Adds comprehensive unit tests and a mock runtime.
## Motivation
- Allow EVM contracts and tooling to interact with Substrate balances
via a familiar ERC20 interface.
- Support off-chain approvals via EIP-2612 for gasless approvals and
improved UX.
## Key Changes
- New crate: `operator/precompiles/erc20-balances`
- Core logic: `src/lib.rs`
- EIP-2612 helpers and validation: `src/eip2612.rs`
- Tests + mock runtime: `src/tests.rs`, `src/mock.rs`
- Runtime wiring (all networks): add `Erc20BalancesPrecompile` at
`AddressU64<2050>`
- `operator/runtime/{mainnet,stagenet,testnet}/src/precompiles.rs`
- Workspace plumbing: include `pallet-evm-precompile-balances-erc20` in
`operator/Cargo.toml`
## Interface
- ERC20: `totalSupply`, `balanceOf`, `allowance`, `approve`, `transfer`,
`transferFrom`, `name`, `symbol`, `decimals`
- Native-only flows: `deposit()` (fallback/payable) and
`withdraw(uint256)`
- EIP-2612: `permit(owner,spender,value,deadline,v,r,s)`,
`nonces(owner)`, `DOMAIN_SEPARATOR()`
- Events: `Transfer`, `Approval`, `Deposit`, `Withdrawal`
- Storage:
- Approvals via `ApprovesStorage` (double map: owner → spender → amount)
- EIP-2612 nonces via `NoncesStorage` keyed by `H160`
- Instance-aware prefixes to support multiple `pallet_balances`
instances
|
2025-09-12 08:57:44 +00:00 |
|