test: uni-v2 pair

[0xrusowsky]

this PR aimed to showcase the impl of a slightly more advanced set of contracts like uniswap-v2 (both pair + factory).

however, it made me realize several limitations of the compilation pipeline, such as the fact that the initial impl was limited to 1 contract per crate. Despite this limitation still holds -we can only have 1 entry point per binary + their bytecode should be independent to reduce contract size and cyclical dependency loops-, i propose a PoC for a more versatile (and complex) compilation process.

r55-compile

• revamped so that users can define several contracts (in separate mods) which share a common project. See uniswap-v2/pair.rs and uniswap-v2/factory.rs.

• the pipeline identifies all the necessary dependencies, including common mods like uniswap-v2/math.rs (for the time being, any module imported on lib.rs which doesn't have a contract is considered common. If we like the PoC, we would enhance AST analysis to only inject the necessary non-contracts mods for each contract). Then it generates an isolates a flattened version of each crate under target/r55-generated/ --> note that right now i only keep them for debugging purposes, but once the output bytecode is generated, they could be auto-cleared by the script itself.

• the pipeline still accounts for compilation order based on contract dependencies, and still generates the deployable impls. However, i added more fine-grained control over contract deps based their intended usecase:

  • interface-only: informed as a regular dep, with its feature flag --> imports the interface to interact with the contract
  • deployable: since deployable impl will be generated after the temp crate (with flattening) creation, users will have to add metadata to the Cargo.toml to inform the module/crate that should be deployable.

  for instance, this toml will crate target/r55-generated/uniswap-v2/factory/deployable.rs with the bytecode of target/r55-generated/uniswap-v2/pair/lib.rs. It will also make erc20::IERC20 available to both binaries.

# uniswap-v2/Cargo.toml

[package.metadata.deployable_deps]
pair = { path = "." }

[dependencies]
erc20 = { path = "../erc20", features = ["interface-only"] }

Built-in reentrancy guard

• added a new storage type Lock which implements a built-in reentrancy guard, UX is quite cool imo, as users only ned to:
  1. initialize the lock in the constructor when deploying the contract.
  2. aquire the guard in the re-entrancy protected fn
• Lock automatically writes back to storage when dropped, releasing the guard

Leverage rust docs for better dev-ex

• auto-generated doc comments for interfaces, so that the LSP shows the available methods

enhanced contract macro to support private fns

• edgecase we hadn't considered before

Address opcode

• added fn address(&self) -> Address to contracts, so that they can know their own address (analogous to address(this) in solidity.

extend MappingGuard

• implemented several core utils like AddAssign to have better mapping UX:

// before
let to_balance = self.balance_of[to].read();
self.balance_of[to].write(to_balance + amount);

// now
self.balance_of[to] += amount;

Pending TODOs:

to be tackled in other PRs

• impl ecrecover
• dynamic storage types (vecs, strings, etc)
• dev-friendly keccack impl passing bytes rather than pointers (super easy, but this PR is already touching so much stuff)
• figure out how to use U8 as it doesn't seem to impl SolValue: https://github.com/alloy-rs/core/blob/cd4b8d5e77e38d71534742fa4fb0505505b2ca2d/crates/sol-types/src/types/value.rs#L221
• impl CREATE 2 (should also be easy now that CREATE is already supported)