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Architecture

revive uses solc, the Ethereum Solidity compiler, as the Solidity frontend to process smart contracts written in Solidity. LLVM, a popular and powerful compiler framework, is used as the compiler backend and does the heavy lifting in terms of optimizitations and RISC-V code generation.

revive mainly takes care of lowering the YUL intermediate representation (IR) produced by solc to LLVM IR. This approach provides a good balance between maintaining a high level of Ethereum compatibility, good contract performance and feasible engineering efforts.

revive vs. resolc nomenclature​

revive is the name of the overarching "Solidity to PolkaVM" compiler project, which contains multiple components (for example the YUL frontend but also the resolc executable itself).

resolc is the name of the single entry-point frontend binary executable, which transparently uses all revive components to produce compiled contract artifacts.

Compilation process​

When compiling a Solidity source file, the following steps happen under the hood:

  1. solc is used to lower the Solidity source code into YUL intermediate representation.
  2. revive lowers the YUL IR into LLVM IR.
  3. LLVM optimizes the code and emits a RISC-V ELF shared object (through LLD).
  4. The PolkaVM linker finally links the ELF shared object into a PolkaVM blob.

This compilation process can be visualized as follows:

Architecture Overview