chore: move is_native_field up into noirc_frontend (noir-lang#5119)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*

This struct is only used for a single check up in `noirc_frontend` so we
should move this logic closer to where it's used.

## Additional Context



## Documentation\*

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

acvm-repo/acir_field/Cargo.toml

@@ -16,7 +16,6 @@ repository.workspace = true
 hex.workspace = true
 num-bigint.workspace = true
 serde.workspace = true
-num-traits.workspace = true
 
 ark-bn254 = { version = "^0.4.0", default-features = false, features = ["curve"] }
 ark-bls12-381 = { version = "^0.4.0", optional = true, default-features = false, features = ["curve"] }

acvm-repo/acir_field/src/lib.rs

@@ -2,9 +2,6 @@
 #![warn(unreachable_pub)]
 #![warn(clippy::semicolon_if_nothing_returned)]
 #![cfg_attr(not(test), warn(unused_crate_dependencies, unused_extern_crates))]
-
-use num_bigint::BigUint;
-use num_traits::Num;
 mod generic_ark;
 
 pub use generic_ark::AcirField;
@@ -15,40 +12,11 @@ pub use generic_ark::FieldElement as GenericFieldElement;
 cfg_if::cfg_if! {
     if #[cfg(feature = "bls12_381")] {
         pub type FieldElement = generic_ark::FieldElement<ark_bls12_381::Fr>;
-        pub const CHOSEN_FIELD : FieldOptions = FieldOptions::BLS12_381;
     } else {
         pub type FieldElement = generic_ark::FieldElement<ark_bn254::Fr>;
-        pub const CHOSEN_FIELD : FieldOptions = FieldOptions::BN254;
     }
 }
 
-#[derive(Debug, PartialEq, Eq)]
-pub enum FieldOptions {
-    BN254,
-    BLS12_381,
-}
-
-impl FieldOptions {
-    pub fn to_string(&self) -> &str {
-        match self {
-            FieldOptions::BN254 => "bn254",
-            FieldOptions::BLS12_381 => "bls12_381",
-        }
-    }
-
-    pub fn is_native_field(str: &str) -> bool {
-        let big_num = if let Some(hex) = str.strip_prefix("0x") {
-            BigUint::from_str_radix(hex, 16)
-        } else {
-            BigUint::from_str_radix(str, 10)
-        };
-        if let Ok(big_num) = big_num {
-            big_num == FieldElement::modulus()
-        } else {
-            CHOSEN_FIELD.to_string() == str
-        }
-    }
-}
 // This is needed because features are additive through the dependency graph; if a dependency turns on the bn254, then it
 // will be turned on in all crates that depend on it
 #[macro_export]

compiler/noirc_frontend/Cargo.toml

@@ -21,13 +21,17 @@ smol_str.workspace = true
 im.workspace = true
 serde_json.workspace = true
 serde.workspace = true
+num-bigint.workspace = true
+num-traits.workspace = true
 rustc-hash = "1.1.0"
 small-ord-set = "0.1.3"
 regex = "1.9.1"
+cfg-if = "1.0.0"
 tracing.workspace = true
 petgraph = "0.6"
 lalrpop-util = { version = "0.20.2", features = ["lexer"] }
 
+
 [dev-dependencies]
 base64.workspace = true
 strum = "0.24"
@@ -39,3 +43,5 @@ lalrpop = "0.20.2"
 
 [features]
 experimental_parser = []
+bn254 = []
+bls12_381 = []

compiler/noirc_frontend/src/hir/def_collector/dc_mod.rs

@@ -1,8 +1,10 @@
 use std::{collections::HashMap, path::Path, vec};
 
-use acvm::acir::acir_field::FieldOptions;
+use acvm::{AcirField, FieldElement};
 use fm::{FileId, FileManager, FILE_EXTENSION};
 use noirc_errors::Location;
+use num_bigint::BigUint;
+use num_traits::Num;
 
 use crate::ast::{
     FunctionDefinition, Ident, ItemVisibility, LetStatement, ModuleDeclaration, NoirFunction,
@@ -233,7 +235,7 @@ impl<'a> ModCollector<'a> {
         for function in functions {
             // check if optional field attribute is compatible with native field
             if let Some(field) = function.attributes().get_field_attribute() {
-                if !FieldOptions::is_native_field(&field) {
+                if !is_native_field(&field) {
                     continue;
                 }
             }
@@ -721,6 +723,29 @@ fn should_check_siblings_for_module(module_path: &Path, parent_path: &Path) -> b
     }
 }
 
+cfg_if::cfg_if! {
+    if #[cfg(feature = "bn254")] {
+        pub const CHOSEN_FIELD: &str = "bn254";
+    } else if #[cfg(feature = "bls12_381")] {
+        pub const CHOSEN_FIELD: &str = "bls12_381";
+    } else {
+        compile_error!("please specify a field to compile with");
+    }
+}
+
+fn is_native_field(str: &str) -> bool {
+    let big_num = if let Some(hex) = str.strip_prefix("0x") {
+        BigUint::from_str_radix(hex, 16)
+    } else {
+        BigUint::from_str_radix(str, 10)
+    };
+    if let Ok(big_num) = big_num {
+        big_num == FieldElement::modulus()
+    } else {
+        CHOSEN_FIELD == str
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

compiler/wasm/Cargo.toml

@@ -17,7 +17,7 @@ acvm = { workspace = true, features = ["bn254"] }
 fm.workspace = true
 nargo.workspace = true
 noirc_driver.workspace = true
-noirc_frontend.workspace = true
+noirc_frontend = { workspace = true, features = ["bn254"] }
 noirc_errors.workspace = true
 noirc_evaluator.workspace = true
 wasm-bindgen.workspace = true

tooling/nargo_cli/Cargo.toml

@@ -29,7 +29,7 @@ nargo_toml.workspace = true
 noir_lsp.workspace = true
 noir_debugger.workspace = true
 noirc_driver.workspace = true
-noirc_frontend.workspace = true
+noirc_frontend = { workspace = true, features = ["bn254"] }
 noirc_abi.workspace = true
 noirc_errors.workspace = true
 acvm = { workspace = true, features = ["bn254"] }

tooling/noirc_abi/Cargo.toml

@@ -23,3 +23,13 @@ num-traits = "0.2"
 [dev-dependencies]
 strum = "0.24"
 strum_macros = "0.24"
+
+[features]
+bn254 = [
+    "acvm/bn254",
+    "noirc_frontend/bn254",
+]
+bls12_381 = [
+    "acvm/bls12_381",
+    "noirc_frontend/bls12_381",
+]

tooling/noirc_abi_wasm/Cargo.toml

@@ -13,7 +13,7 @@ crate-type = ["cdylib"]
 
 [dependencies]
 acvm = { workspace = true, features = ["bn254"] }
-noirc_abi.workspace = true
+noirc_abi = { workspace = true, features = ["bn254"] }
 iter-extended.workspace = true
 wasm-bindgen.workspace = true
 serde.workspace = true