/era-compiler-solidity

EraVM Solidity compiler.

Primary LanguageRustApache License 2.0Apache-2.0

zkSync Era: Solidity Compiler

Logo

zkSync Era is a layer 2 rollup that uses zero-knowledge proofs to scale Ethereum without compromising on security or decentralization. As it’s EVM-compatible (with Solidity/Vyper), 99% of Ethereum projects can redeploy without needing to refactor or re-audit any code. zkSync Era also uses an LLVM-based compiler that will eventually enable developers to write smart contracts in popular languages such as C++ and Rust.

This repository contains the EraVM Solidity compiler.

System Requirements

Supported platforms:

  • Linux: x86_64
    MUSL-based static builds do not depend on system libraries and can be run on any recent Linux distribution.
  • MacOS 11+: x86_64, arm64 (M1, M2)
  • Windows: x86_64
    Only Windows 10 has been tested so far, but other versions should be OK as well.

We recommend at least 4 GB of RAM available for the build process.

Delivery Methods

  1. Install via npm
    Use zkSync CLI to obtain a compiler package and prepare a project environment. After the installation you can modify a hardhat configuration file in the project and specify zksolc version there. Use npx hardhat compile or yarn hardhat compile to compile. @matterlabs/hardhat-zksync-solc package will be used from npm repo.
  2. Download prebuilt binaries
    Download solc and zksolc binaries directly from GitHub. Use the CLI or Hardhat to compile contracts.
  3. Build binaries from sources
    Build binaries using the guide below. Use the CLI or Hardhat to compile contracts.

Building

  1. Install some tools system-wide:
    1.a. apt install cmake ninja-build clang-13 lld-13 parallel on a Debian-based Linux, with optional musl-tools if you need a musl build.
    1.b. pacman -S cmake ninja clang lld parallel on an Arch-based Linux.
    1.c. On MacOS, install the HomeBrew package manager (being careful to install it as the appropriate user), then brew install cmake ninja coreutils parallel. Install your choice of a recent LLVM/Clang compiler, e.g. via Xcode, Apple’s Command Line Tools, or your preferred package manager.
    1.d. Their equivalents with other package managers.

  2. Install Rust

    Currently we are not pinned to any specific version of Rust, so just install the latest stable build for your platform.
    Also install the musl target if you are compiling on Linux in order to distribute the binary:
    rustup target add x86_64-unknown-linux-musl

  3. Download a version of the solc compiler compiler.
    If it is not named exactly solc and in your $PATH, see the --solc option below.

  4. Check out or clone the appropriate branch of this repository.

  5. Go to the project root and run git checkout <ref> with the tag, branch, or commit you want to build.

  6. Install the EraVM LLVM framework builder:
    6.a. cargo install compiler-llvm-builder on MacOS, or Linux for personal use.
    6.b. cargo install compiler-llvm-builder --target x86_64-unknown-linux-musl on Linux for distribution.

    The builder is not the EraVM LLVM framework itself; it is just a tool that clones our repository and runs the sequence of build commands. By default it is installed in ~/.cargo/bin/, which is recommended to be added to your $PATH. Execute zkevm-llvm --help for more information.
    If you need a specific branch of EraVM LLVM, change it in the LLVM.lock file at the root of this repository.

  7. Run the builder to clone and build the EraVM LLVM framework at this repository root:
    7.1. zkevm-llvm clone
    7.2. zkevm-llvm build

  8. Build the Solidity compiler executable:
    8.a. cargo build --release on MacOS or Linux for personal use.
    8.b. cargo build --release --target x86_64-unknown-linux-musl on Linux for distribution.

  9. If you need to move the built binary elsewhere, grab it from the build directory:
    9.a. On MacOS or Linux for the default target: ./target/release/zksolc
    9.b. On Linux, if you are building for the target x86_64-unknown-linux-musl: ./target/x86_64-unknown-linux-musl/release/zksolc

Usage

Check ./target/*/zksolc --help for the compiler usage.

The solc compiler must be available in $PATH, or its path must be passed explicitly with the --solc option.

For big projects it is more convenient to use the compiler via the Hardhat plugin. For single-file contracts, or small projects, the CLI suffices.

Unit testing

For running unit tests, zksolc itself must also be available in $PATH, because it calls itself recursively to allow compiling each contract in a separate process. To successfully run unit tests:

  1. Run cargo build --release.
  2. Move the binary from ./target/release/zksolc to a directory from $PATH, or add the target directory itself to $PATH.
  3. Run cargo test.

CLI testing

For running command line interface tests, zksolc itself and solc must also be available in $PATH, because it calls itself recursively to allow compiling each contract in a separate processes. To successfully run CLI tests:

  1. Go to cli-tests.
  2. Make npm i.
  3. Add solc and zksolc to $PATH.
  4. Run npm test.

Troubleshooting

  • If you get a “failed to authenticate when downloading repository… if the git CLI succeeds then net.git-fetch-with-cli may help here” error, then prepending the cargo command with CARGO_NET_GIT_FETCH_WITH_CLI=true may help.
  • On MacOS, git config --global credential.helper osxkeychain followed by cloning a repository manually with a personal access token may help.
  • Unset any LLVM-related environment variables you may have set, especially LLVM_SYS_<version>_PREFIX (see e.g. https://crates.io/crates/llvm-sys and https://llvm.org/docs/GettingStarted.html#local-llvm-configuration). To make sure: set | grep LLVM

License

The Solidity compiler is distributed under the terms of either

at your option.

Resources

zkSync Era compiler toolchain documentation

Solidity documentation

Official Links

Disclaimer

zkSync Era has been through extensive testing and audits, and although it is live, it is still in alpha state and will undergo further audits and bug bounty programs. We would love to hear our community's thoughts and suggestions about it! It's important to note that forking it now could potentially lead to missing important security updates, critical features, and performance improvements.