Compiling Rust code
This tutorial demonstrates how an .rs file can be converted into a circuit IR.
The flow for compiling Rust code is similar to compiling any other cargo project. The only notable difference is specifying a different build target for cargo while the rest of the Rust developer experience remains the same.
Using cargo from a pre-built binary
If cargo has been installed from a pre-built binary, run the following command.
cargo +zkllvm build --target assigner-unknown-unknown --release
After the build procedure is complete, the resulting .ll file will appear in the ./target/assigner-unknown-unknown/release directory. The file will have the same name as the name of the current cargo crate.
Using cargo from sources
If cargo has been installed from sources, export the RUSTC and CARGO environmental variables.
export CARGO="path/to/cargo"
export RUSTC="path/to/rustc"
cargo should be located in "/zkllvm/build/libs/rslang/build/host/stage2-tools-bin/cargo".
rustc should be located in "zkllvm/build/libs/rslang/build/host/stage2/bin".
Then, execute the following command.
RUSTC=$RUSTC $CARGO build --target assigner-unknown-unknown --release
The resulting .ll file should be located in the ./target/assigner-unknown-unknown/release folder.
Using rustc directly
While using rustc instead of cargo is unconventional, it is still possible to call the compiler directly to produce .ll files.
If rustc has been installed as from a pre-built binary, run this command.
rustc +zkllvm --target assigner-unknown-unknown --emit=llvm-ir path/to/circuit.rs -C opt-level=3
If rustc has been installed from sources, execute the following command.
$RUSTC --target assigner-unknown-unknown --emit=llvm-ir path/to/circuit.rs -C opt-level=3
The -C opt-level=3 option is needed to build the circuit into an IR that is most compatible with assigner. If it is ommitted, the IR will contain additional verbose code which may hinder assigner from generating constraints and the assignment table.