hardhat-zksync-solc

This plugin is used to provide a convenient interface for compiling Solidity smart contracts before deploying them to zkSync Era.

Installation

@matterlabs/hardhat-zksync-solc

Add the latest version of this plugin to your project with the following command:

# Yarn
yarn add -D @matterlabs/hardhat-zksync-solc

# Npm
npm i -D @matterlabs/hardhat-zksync-solc

Exports

This plugin most often will not be used directly in the code.

Configuration

This plugin is configured in the hardhat.config.ts file of your project. Here is an example

zksolc: {
  version: "1.3.5",
  compilerSource: "binary",  // binary or docker (deprecated)
  settings: {
    compilerPath: "zksolc",  // ignored for compilerSource: "docker"
    experimental: {
      dockerImage: "matterlabs/zksolc", // Deprecated: used for compilerSource: "docker"
      tag: "latest"   // Deprecated: used for compilerSource: "docker"
    },
    libraries:{}, // optional. References to non-inlinable libraries
    isSystem: false, // optional.  Enables Yul instructions available only for zkSync system contracts and libraries
    forceEvmla: false // optional. Falls back to EVM legacy assembly if there is a bug with Yul
  }
}
networks: {
  hardhat: {
    zksync: true  // enables zksync in hardhat local network
  }
}

Note

Compilers are no longer released as Docker images and its usage is no longer recommended. Use the compilerSource: "binary" in the Hardhat config file to use the binary instead.

• version is a field with the version of the zksolc compiler. Compiler versions can be found in the following repository.
• compilerSource indicates the compiler source and can be either docker or binary (recommended). If there isn't a compiler binary already installed, the plugin will automatically download it. If docker is used, you'd need to run Docker desktop in the background and provide both dockerImage and tag in the experimental section.
• compilerPath (optional) is a field with the path to the zksolc binary. By default, the binary in $PATH is used. If compilerSource is docker, this field is ignored.
• dockerImage and tag make up the name of the compiler docker image. If compilerSource is binary, these fields are ignored.
• libraries if your contract uses non-inlinable libraries as dependencies, they have to be defined here. Learn more about compiling libraries here
• isSystem - required if contracts use enables Yul instructions available only for zkSync system contracts and libraries
• forceEvmla - falls back to EVM legacy assembly if there is a bug with Yul
• zksync network option indicates whether zksolc is enabled on a certain network. false by default. Useful for multichain projects in which you can enable zksync only for specific networks.

`forceEvmla` usage

Setting the forceEvmla field to true can have the following negative impacts:

• No support for recursion.
• No support for internal function pointers.
• Contract size or performance impact.

For solidity versions older than 0.8, this setting is enforced by default when compiling.

Commands

hardhat compile -- compiles all the smart contracts in the contracts directory and creates the artifacts-zk folder with all the compilation artifacts, including factory dependencies for the contracts, which could be used for contract deployment.

To understand what the factory dependencies are, read more about them in the Web3 API documentation.