chore: allow one to compile a circuit without a backend being specified

acvm-repo/acir/Cargo.toml

@@ -19,12 +19,12 @@ serde.workspace = true
 thiserror.workspace = true
 flate2 = "1.0.24"
 bincode.workspace = true
+strum = "0.24"
+strum_macros = "0.24"
 base64.workspace = true
 
 [dev-dependencies]
 serde_json = "1.0"
-strum = "0.24"
-strum_macros = "0.24"
 serde-reflection = "0.3.6"
 serde-generate = "0.25.1"
 fxhash.workspace = true

acvm-repo/acir/src/circuit/black_box_functions.rs

@@ -5,12 +5,11 @@
 //! These are implemented inside the ACVM stdlib.
 
 use serde::{Deserialize, Serialize};
-#[cfg(test)]
+use strum::IntoEnumIterator;
 use strum_macros::EnumIter;
 
 #[allow(clippy::upper_case_acronyms)]
-#[derive(Clone, Debug, Hash, Copy, PartialEq, Eq, Serialize, Deserialize)]
-#[cfg_attr(test, derive(EnumIter))]
+#[derive(Clone, Debug, Hash, Copy, PartialEq, Eq, Serialize, Deserialize, EnumIter)]
 pub enum BlackBoxFunc {
     /// Bitwise AND.
     AND,
@@ -99,6 +98,10 @@ impl BlackBoxFunc {
     pub fn is_valid_black_box_func_name(op_name: &str) -> bool {
         BlackBoxFunc::lookup(op_name).is_some()
     }
+
+    pub fn all_blackbox_functions() -> Vec<String> {
+        Self::iter().map(|x| x.name().to_string()).collect()
+    }
 }
 
 #[cfg(test)]

tooling/backend_interface/src/lib.rs

@@ -9,6 +9,7 @@ mod proof_system;
 mod smart_contract;
 
 use acvm::acir::circuit::Opcode;
+use acvm::acir::BlackBoxFunc;
 use bb_abstraction_leaks::ACVM_BACKEND_BARRETENBERG;
 use bb_abstraction_leaks::BB_VERSION;
 use cli::VersionCommand;
@@ -141,6 +142,16 @@ pub struct BackendOpcodeSupport {
 }
 
 impl BackendOpcodeSupport {
+    pub fn all_opcodes_supported() -> Self {
+        BackendOpcodeSupport {
+            opcodes: vec!["arithmetic", "directive", "brillig", "memory_init", "memory_op"]
+                .into_iter()
+                .map(|s| s.to_string())
+                .collect(),
+            black_box_functions: BlackBoxFunc::all_blackbox_functions().into_iter().collect(),
+        }
+    }
+
     pub fn is_opcode_supported(&self, opcode: &Opcode) -> bool {
         match opcode {
             Opcode::Arithmetic(_) => self.opcodes.contains("arithmetic"),

tooling/nargo_cli/src/cli/compile_cmd.rs

@@ -41,6 +41,10 @@ pub(crate) struct CompileCommand {
     #[arg(long)]
     include_keys: bool,
 
+    /// Compile without a backend
+    #[clap(long, default_value = "false", hide = true)]
+    no_backend: bool,
+
     /// The name of the package to compile
     #[clap(long, conflicts_with = "workspace")]
     package: Option<CrateName>,
@@ -76,7 +80,12 @@ pub(crate) fn run(
         .cloned()
         .partition(|package| package.is_binary());
 
-    let (np_language, opcode_support) = backend.get_backend_info()?;
+    let (np_language, opcode_support) = if args.no_backend {
+        (Language::PLONKCSat { width: 3 }, BackendOpcodeSupport::all_opcodes_supported())
+    } else {
+        backend.get_backend_info()?
+    };
+
     let (_, compiled_contracts) = compile_workspace(
         &workspace,
         &binary_packages,

tooling/nargo_cli/src/cli/execute_cmd.rs

@@ -1,4 +1,6 @@
 use acvm::acir::native_types::WitnessMap;
+use acvm::Language;
+use backend_interface::BackendOpcodeSupport;
 use clap::Args;
 
 use nargo::artifacts::debug::DebugArtifact;
@@ -24,6 +26,10 @@ pub(crate) struct ExecuteCommand {
     /// Write the execution witness to named file
     witness_name: Option<String>,
 
+    /// Compile without a backend
+    #[clap(long, default_value = "false", hide = true)]
+    no_backend: bool,
+
     /// The name of the toml file which contains the inputs for the prover
     #[clap(long, short, default_value = PROVER_INPUT_FILE)]
     prover_name: String,
@@ -56,7 +62,12 @@ pub(crate) fn run(
     )?;
     let target_dir = &workspace.target_directory_path();
 
-    let (np_language, opcode_support) = backend.get_backend_info()?;
+    let (np_language, opcode_support) = if args.no_backend {
+        (Language::PLONKCSat { width: 3 }, BackendOpcodeSupport::all_opcodes_supported())
+    } else {
+        backend.get_backend_info()?
+    };
+
     for package in &workspace {
         let compiled_program = compile_bin_package(
             &workspace,

tooling/nargo_cli/tests/rebuild.sh

@@ -27,7 +27,7 @@ for dir in $base_path/*; do
       if [ -d ./target/ ]; then
         rm -r ./target/
       fi
-      nargo compile && nargo execute witness
+      nargo compile --no-backend && nargo execute --no-backend witness
 
       # Rename witness.tr to witness.gz
       if [ -f ./target/witness.tr ]; then