add frontend features to reduce the amount of dependencies and compil…

…ation time

The reasoning behind this is that compilation time now is too long, in
part because dependencies on specific frontends, so if the compilation
don't use some frontend it can be turned off by default.

.github/workflows/ci.yml

@@ -69,10 +69,10 @@ jobs:
       - name: Build
         # This build will be reused by nextest,
         # and also checks (--all-targets) that benches don't bit-rot
-        run: cargo build --release --all-targets --no-default-features --features "light-test,${{ matrix.feature }}"
+        run: cargo build --release --all-targets --no-default-features --features "light-test,circom,noname,noir,${{ matrix.feature }}"
       - name: Test
         run: |
-          cargo nextest run --profile ci --release --workspace --no-default-features --features "light-test,${{ matrix.feature }}"
+          cargo nextest run --profile ci --release --workspace --no-default-features --features "light-test,circom,noname,noir,${{ matrix.feature }}"
       - name: Doctests # nextest does not support doc tests
         run: |
           cargo test --doc

README.md

@@ -34,6 +34,7 @@ Available frontends to define the folded circuit:
 - [arkworks](https://github.com/arkworks-rs), arkworks contributors
 - [Circom](https://github.com/iden3/circom), iden3, 0Kims Association
 - [Noname](https://github.com/zksecurity/noname), zkSecurity
+- [Noir](https://github.com/noir-lang/noir), Aztec
 
 ## Usage
 

examples/circom_full_flow.rs

@@ -2,6 +2,9 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::upper_case_acronyms)]
 ///
+/// To run:
+/// > cargo run --release --example noir_full_flow -- --nocapture
+///
 /// This example performs the full flow:
 /// - define the circuit to be folded
 /// - fold the circuit with Nova+CycleFold's IVC

examples/external_inputs.rs

@@ -3,6 +3,9 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::upper_case_acronyms)]
 
+///
+/// To run:
+/// > cargo run --release --example external_inputs -- --nocapture
 use ark_bn254::{constraints::GVar, Bn254, Fr, G1Projective as Projective};
 use ark_crypto_primitives::{
     crh::{

examples/full_flow.rs

@@ -2,6 +2,9 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::upper_case_acronyms)]
 ///
+/// To run:
+/// > cargo run --release --example full_flow -- --nocapture
+///
 /// This example performs the full flow:
 /// - define the circuit to be folded
 /// - fold the circuit with Nova+CycleFold's IVC

examples/multi_inputs.rs

@@ -3,6 +3,9 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::upper_case_acronyms)]
 
+///
+/// To run:
+/// > cargo run --release --example multi_inputs -- --nocapture
 use ark_ff::PrimeField;
 use ark_r1cs_std::alloc::AllocVar;
 use ark_r1cs_std::fields::fp::FpVar;

examples/noir_full_flow.rs

@@ -2,6 +2,9 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::upper_case_acronyms)]
 ///
+/// To run:
+/// > cargo run --release --example noir_full_flow -- --nocapture
+///
 /// This example performs the full flow:
 /// - define the circuit to be folded
 /// - fold the circuit with Nova+CycleFold's IVC

examples/noname_full_flow.rs

@@ -2,6 +2,9 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::upper_case_acronyms)]
 ///
+/// To run:
+/// > cargo run --release --example noname_full_flow -- --nocapture
+///
 /// This example performs the full flow:
 /// - define the circuit to be folded
 /// - fold the circuit with Nova+CycleFold's IVC

examples/sha256.rs

@@ -3,6 +3,9 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::upper_case_acronyms)]
 
+///
+/// To run:
+/// > cargo run --release --example sha256 -- --nocapture
 use ark_crypto_primitives::crh::{
     sha256::{
         constraints::{Sha256Gadget, UnitVar},

folding-schemes/Cargo.toml

@@ -15,7 +15,6 @@ ark-relations = { version = "^0.4.0", default-features = false }
 ark-r1cs-std = { version = "0.4.0", default-features = false } # this is patched at the workspace level
 ark-snark = { version = "^0.4.0"}
 ark-serialize = "^0.4.0"
-ark-circom = { git = "https://github.com/arnaucube/circom-compat" }
 thiserror = "1.0"
 rayon = "1.7.0"
 num-bigint = "0.4"
@@ -24,17 +23,20 @@ color-eyre = "=0.6.2"
 ark-bn254 = {version="0.4.0"}
 ark-groth16 = { version = "^0.4.0" }
 sha3 = "0.10"
-ark-noname = { git = "https://github.com/dmpierre/ark-noname", branch="feat/sonobe-integration" }
-noname = { git = "https://github.com/dmpierre/noname" }
 serde_json = "1.0.85"                                                                # to (de)serialize JSON
 serde = "1.0.203"
-acvm = { git = "https://github.com/noir-lang/noir", rev="2b4853e", default-features = false }
-arkworks_backend = { git = "https://github.com/dmpierre/arkworks_backend", branch="feat/sonobe-integration" }
 log = "0.4"
 
 # tmp import for espresso's sumcheck
 espresso_subroutines = {git="https://github.com/EspressoSystems/hyperplonk", package="subroutines"}
 
+# frontend dependencies:
+ark-circom = { git = "https://github.com/arnaucube/circom-compat", optional=true }
+noir_arkworks_backend = { package="arkworks_backend", git = "https://github.com/dmpierre/arkworks_backend", branch="feat/sonobe-integration", optional=true }
+acvm = { git = "https://github.com/noir-lang/noir", rev="2b4853e", default-features = false, optional=true }
+noname = { git = "https://github.com/dmpierre/noname", optional=true }
+ark-noname = { git = "https://github.com/dmpierre/ark-noname", branch="feat/sonobe-integration", optional=true }
+
 [dev-dependencies]
 ark-pallas = {version="0.4.0", features=["r1cs"]}
 ark-vesta = {version="0.4.0", features=["r1cs"]}
@@ -46,7 +48,14 @@ tracing-subscriber = { version = "0.2" }
 
 [features]
 default = ["parallel"]
+# 'light-test' is a feature disabled by default, that when enabled will affect
+# the DeciderEthCircuit implementations, skipping the heavy-weight parts of the
+# circuit, allowing to run light tests of it taking less time.
 light-test = []
+# frontend features:
+circom = ["dep:ark-circom"]
+noname = ["dep:noname", "dep:ark-noname"]
+noir = ["dep:acvm", "dep:noir_arkworks_backend"]
 
 parallel = [ 
     "ark-std/parallel", 

folding-schemes/src/frontend/mod.rs

@@ -4,8 +4,13 @@ use ark_r1cs_std::fields::fp::FpVar;
 use ark_relations::r1cs::{ConstraintSystemRef, SynthesisError};
 use ark_std::fmt::Debug;
 
+// we use features to activate specific frontends, to reduce the amount of dependencies and compile
+// time
+#[cfg(feature = "circom")]
 pub mod circom;
+#[cfg(feature = "noir")]
 pub mod noir;
+#[cfg(feature = "noname")]
 pub mod noname;
 
 /// FCircuit defines the trait of the circuit of the F function, which is the one being folded (ie.

folding-schemes/src/frontend/noir/mod.rs

@@ -16,7 +16,7 @@ use ark_ff::PrimeField;
 use ark_r1cs_std::{alloc::AllocVar, fields::fp::FpVar, R1CSVar};
 use ark_relations::r1cs::ConstraintSynthesizer;
 use ark_relations::r1cs::{ConstraintSystemRef, SynthesisError};
-use arkworks_backend::{read_program_from_file, sonobe_bridge::AcirCircuitSonobe};
+use noir_arkworks_backend::{read_program_from_file, sonobe_bridge::AcirCircuitSonobe};
 
 #[derive(Clone, Debug)]
 pub struct NoirFCircuit<F: PrimeField> {

solidity-verifiers/Cargo.toml

@@ -28,7 +28,8 @@ tracing-subscriber = { version = "0.2" }
 ark-bn254 = {version="0.4.0", features=["r1cs"]}
 ark-grumpkin = {version="0.4.0", features=["r1cs"]}
 rand = "0.8.5"
-folding-schemes = { path = "../folding-schemes/", features=["light-test"]}
+# use the diverse frontend features for the examples
+folding-schemes = { path = "../folding-schemes/", features=["light-test", "circom", "noname", "noir"]}
 noname = { git = "https://github.com/dmpierre/noname" }
 
 [features]
@@ -56,4 +57,3 @@ path = "../examples/noname_full_flow.rs"
 [[example]]
 name = "noir_full_flow"
 path = "../examples/noir_full_flow.rs"
-