Merge pull request #12 from worldcoin/remco/update-ark-circom

Update ark circom

Cargo.toml

@@ -26,7 +26,7 @@ required-features = [ "bench", "proptest" ]
 
 [dependencies]
 ark-bn254 = { version = "0.3.0" }
-ark-circom = { git = "https://github.com/gakonst/ark-circom", features=["circom-2"] }
+ark-circom = { git = "https://github.com/gakonst/ark-circom", rev="a93c8b0", features=["circom-2"] }
 ark-ec = { version = "0.3.0", default-features = false, features = ["parallel"] }
 ark-ff = { version = "0.3.0", default-features = false, features = ["parallel", "asm"] }
 ark-groth16 = { git = "https://github.com/arkworks-rs/groth16", rev = "765817f", features = ["parallel"] }
@@ -46,9 +46,9 @@ rand = "0.8.4"
 rayon = "1.5.1"
 serde = "1.0"
 sha2 = "0.10.1"
-tempfile = "3.3.0"
 thiserror = "1.0.0"
 tiny-keccak = { version = "2.0.2" }
+wasmer = { version = "2.0", features = [ "dylib" ] }
 zkp-u256 = { version = "0.2", optional = true } # TODO: Remove
 
 # Use the same `ethers-core` version as ark-circom
@@ -64,8 +64,8 @@ tempfile = "3.0"
 tiny-keccak = "2.0.2"
 tracing-test = "0.2"
 
-# [patch.crates-io]
-# wasmer = { git = 'https://github.com/philsippl/wasmer', rev = "e776616"}
+wasmer-engine-dylib = "2.2.1"
+wasmer-compiler-cranelift = "2.2.1"
 
 [profile.release]
 codegen-units = 1

examples/dylib.rs

@@ -0,0 +1,40 @@
+use wasmer::{Module, Store};
+use wasmer_compiler_cranelift::Cranelift;
+use wasmer_engine_dylib::Dylib;
+
+const PATH: &str = "../semaphore/build/snark/semaphore.wasm";
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Define a compiler configuration.
+    //
+    // In this situation, the compiler is
+    // `wasmer_compiler_cranelift`. The compiler is responsible to
+    // compile the Wasm module into executable code.
+    let compiler_config = Cranelift::default();
+
+    println!("Creating Dylib engine...");
+    // Define the engine that will drive everything.
+    //
+    // In this case, the engine is `wasmer_engine_dylib` which means
+    // that a shared object is going to be generated.
+    let engine = Dylib::new(compiler_config).engine();
+
+    // Create a store, that holds the engine.
+    let store = Store::new(&engine);
+
+    println!("Compiling module...");
+    // Here we go.
+    //
+    // Let's compile the Wasm module. It is at this step that the Wasm
+    // text is transformed into Wasm bytes (if necessary), and then
+    // compiled to executable code by the compiler, which is then
+    // stored into a shared object by the engine.
+    let module = Module::from_file(&store, "../semaphore/build/snark/semaphore.wasm")?;
+
+    println!("Storing as \"{}\"", PATH);
+    module.serialize_to_file(PATH)?;
+
+    println!("Done! you can now compile with CIRCUIT_WASM_DYLIB=\"{}\"", PATH);
+
+    Ok(())
+}

examples/dylib_ios.rs

@@ -0,0 +1,63 @@
+//! This builds the wasm file into a dylib for a given target platform. 
+//!
+//! ```shell
+//! cargo run --example dylib_ios aarch64-apple-ios semaphore/build/snark/semaphore.wasm semaphore/build/snark/semaphore.dylib
+//! ```
+//!
+//! Ready?
+
+
+use std::{str::FromStr};
+
+use wasmer::{Module, Store, Triple, RuntimeError, CpuFeature, Target};
+use wasmer_compiler_cranelift::Cranelift;
+use wasmer_engine_dylib::Dylib;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+
+    // to build for ios: aarch64-apple-ios, aarch64-apple-ios-sim, x86_64-apple-ios
+    let target_os = std::env::args().nth(1).expect("no target given"); 
+    let wasm_path = std::env::args().nth(2).expect("no wasm path given");
+    let dylib_path = std::env::args().nth(3).expect("no dylib path given");
+
+    // Define a compiler configuration.
+    //
+    // In this situation, the compiler is
+    // `wasmer_compiler_cranelift`. The compiler is responsible to
+    // compile the Wasm module into executable code.
+    let compiler_config = Cranelift::default();
+
+    let triple = Triple::from_str(&target_os)
+        .map_err(|error| RuntimeError::new(error.to_string()))?;
+
+    // Let's build the target.
+    let mut cpu_feature = CpuFeature::set();
+    cpu_feature.insert(CpuFeature::from_str("sse2")?);
+    let target = Target::new(triple, cpu_feature);
+    println!("Chosen target: {:?}", target);
+
+    println!("Creating Dylib engine...");
+    // Define the engine that will drive everything.
+    //
+    // In this case, the engine is `wasmer_engine_dylib` which means
+    // that a shared object is going to be generated.
+    let engine = Dylib::new(compiler_config).target(target).engine();
+
+    // Create a store, that holds the engine.
+    let store = Store::new(&engine);
+
+    println!("Compiling module...");
+    // Here we go.
+    //
+    // Let's compile the Wasm module. It is at this step that the Wasm
+    // text is transformed into Wasm bytes (if necessary), and then
+    // compiled to executable code by the compiler, which is then
+    // stored into a shared object by the engine.
+    let module = Module::from_file(&store, &wasm_path)?;
+
+    module.serialize_to_file(&dylib_path)?;
+
+    println!("Done! you can now compile with CIRCUIT_WASM_DYLIB=\"{}\"", &dylib_path);
+
+    Ok(())
+}

src/circuit.rs

@@ -4,13 +4,11 @@ use ark_groth16::ProvingKey;
 use ark_relations::r1cs::ConstraintMatrices;
 use core::include_bytes;
 use once_cell::sync::Lazy;
-use std::{
-    io::{Cursor, Write},
-    sync::Mutex,
-};
-use tempfile::NamedTempFile;
+use std::{io::Cursor, sync::Mutex};
+use wasmer::{Dylib, Module, Store};
 
 const ZKEY_BYTES: &[u8] = include_bytes!("../semaphore/build/snark/semaphore_final.zkey");
+
 const WASM: &[u8] = include_bytes!("../semaphore/build/snark/semaphore.wasm");
 
 pub static ZKEY: Lazy<(ProvingKey<Bn254>, ConstraintMatrices<Fr>)> = Lazy::new(|| {
@@ -19,12 +17,20 @@ pub static ZKEY: Lazy<(ProvingKey<Bn254>, ConstraintMatrices<Fr>)> = Lazy::new(|
 });
 
 pub static WITNESS_CALCULATOR: Lazy<Mutex<WitnessCalculator>> = Lazy::new(|| {
-    // HACK: ark-circom requires a file, so we make one!
-    let mut tmpfile = NamedTempFile::new().expect("Failed to create temp file");
-    let written = tmpfile.write(WASM).expect("Failed to write to temp file");
-    assert_eq!(written, WASM.len());
-    let path = tmpfile.into_temp_path();
-    let result = WitnessCalculator::new(&path).expect("Failed to create witness calculator");
-    path.close().expect("Could not remove tempfile");
+    // Create Wasm module
+    let module = if let Some(path) = option_env!("CIRCUIT_WASM_DYLIB") {
+        let store = Store::new(&Dylib::headless().engine());
+        // The module must be exported using [`Module::serialize`].
+        unsafe {
+            Module::deserialize_from_file(&store, path).expect("Failed to load wasm dylib module")
+        }
+    } else {
+        let store = Store::default();
+        Module::from_binary(&store, WASM).expect("wasm should be valid")
+    };
+
+    // Create witness calculator
+    let result =
+        WitnessCalculator::from_module(module).expect("Failed to create witness calculator");
     Mutex::new(result)
 });