revive

YUL and EVM assembly recompiler to LLVM, targetting RISC-V on PolkaVM.

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Status

This is experimental software in active development and not ready just yet for production usage. Please do report any compiler related issues or missing features that are not yet known to us here.

Discussion around the development is hosted on the Polkadot Forum.

Installation

resolc depends on the solc binary installed on your system.

Building from source requires a compatible LLVM build.

LLVM

revive requires a build of LLVM v18.1.8 with the RISC-V embedded target, including compiler-rt. Use the provided revive-llvm utility to compile a compatible LLVM build locally and point $LLVM_SYS_181_PREFIX to the installation directory afterwards.

The resolc Solidity frontend

To install the resolc Solidity frontend executable:

# Build the host LLVM dependency with PolkaVM target support
make install-llvm
export LLVM_SYS_181_PREFIX=${PWD}/target-llvm/gnu/target-final

# Build the resolc frontend executable
make install-bin
resolc --version

Cross-compilation to WASM

Cross-compile resolc.js frontend executable to Wasm for running it in a Node.js or browser environment. The REVIVE_LLVM_TARGET_PREFIX environment variable is used to control the target environment LLVM dependency.

# Build the host LLVM dependency with PolkaVM target support
make install-llvm
export LLVM_SYS_181_PREFIX=${PWD}/target-llvm/gnu/target-final

# Build the target LLVM dependency with PolkaVM target support
revive-llvm --target-env emscripten clone
source emsdk/emsdk_env.sh
revive-llvm --target-env emscripten build
export REVIVE_LLVM_TARGET_PREFIX=${PWD}/target-llvm/emscripten/target-final

# Build the resolc frontend executable
make install-wasm
make test-wasm

Development

Please consult the Makefile targets to learn how to run tests and benchmarks. Ensure that your branch passes make test locally when submitting a pull request.

Design overview

revive uses solc, the Ethereum Solidity compiler, as the Solidity frontend to process smart contracts written in Solidity. The YUL IR code (or legacy EVM assembly as a fallback for older solc versions) emitted by solc is then translated to LLVM IR, targetting Polkadots revive pallet. Frontend and code generator are based of ZKSync zksolc.

Tests

Before running the tests, ensure that Geth (Go Ethereum) is installed on your system. Follow the installation guide here: Installing Geth. Once Geth is installed, you can run the tests using the following command:

make test