feat: Implement basic contracts

crates/nargo/src/cli/compile_cmd.rs

@@ -1,5 +1,7 @@
 use acvm::acir::circuit::Circuit;
 use acvm::ProofSystemCompiler;
+use noirc_driver::Driver;
+use noirc_frontend::node_interner::FuncId;
 use std::path::{Path, PathBuf};
 
 use clap::Args;
@@ -18,48 +20,75 @@ pub(crate) struct CompileCommand {
     /// Issue a warning for each unused variable instead of an error
     #[arg(short, long)]
     allow_warnings: bool,
-}
-
-pub(crate) fn run(args: CompileCommand, config: NargoConfig) -> Result<(), CliError> {
-    let mut circuit_path = config.program_dir.clone();
-    circuit_path.push(TARGET_DIR);
 
-    let circuit_path = compile_and_preprocess_circuit(
-        &args.circuit_name,
-        config.program_dir,
-        circuit_path,
-        args.allow_warnings,
-    )?;
+    /// Compile each contract function used within the program
+    #[arg(short, long)]
+    contracts: bool,
+}
 
-    println!("Generated ACIR code into {}", circuit_path.display());
+pub(crate) fn run(mut args: CompileCommand, config: NargoConfig) -> Result<(), CliError> {
+    let driver = check_crate(&config.program_dir, args.allow_warnings)?;
+
+    let mut circuit_dir = config.program_dir;
+    circuit_dir.push(TARGET_DIR);
+
+    // If contracts is set we're compiling every function in a 'contract' rather than just 'main'.
+    if args.contracts {
+        let circuit_name = args.circuit_name.clone();
+
+        for contract in driver.get_all_contracts() {
+            for function in contract.functions {
+                let name = driver.function_name(function);
+                args.circuit_name = format!("{}-{}-{name}", circuit_name, &contract.name);
+                compile_and_save_program(&driver, function, &args, &circuit_dir)?;
+            }
+        }
+        Ok(())
+    } else {
+        let main = driver.main_function();
+        compile_and_save_program(&driver, main, &args, &circuit_dir)
+    }
+}
 
-    Ok(())
+fn setup_driver(program_dir: impl AsRef<Path>) -> Result<Driver, CliError> {
+    let backend = crate::backends::ConcreteBackend;
+    let mut driver = Resolver::resolve_root_config(program_dir.as_ref(), backend.np_language())?;
+    add_std_lib(&mut driver);
+    Ok(driver)
 }
 
-fn compile_and_preprocess_circuit<P: AsRef<Path>>(
-    circuit_name: &str,
-    program_dir: P,
-    circuit_dir: P,
-    allow_warnings: bool,
-) -> Result<PathBuf, CliError> {
-    let compiled_program = compile_circuit(program_dir, false, allow_warnings)?;
-    let circuit_path = save_program_to_file(&compiled_program, circuit_name, &circuit_dir);
+/// Compile and save a program to disk with the given main function.
+fn compile_and_save_program(
+    driver: &Driver,
+    main: FuncId,
+    args: &CompileCommand,
+    circuit_dir: &Path,
+) -> Result<(), CliError> {
+    let compiled_program = driver
+        .compile_no_check(false, args.allow_warnings, main, true)
+        .map_err(|_| CliError::Generic(format!("'{}' failed to compile", args.circuit_name)))?;
+
+    let circuit_path = save_program_to_file(&compiled_program, &args.circuit_name, circuit_dir);
 
-    preprocess_with_path(circuit_name, circuit_dir, &compiled_program.circuit)?;
+    preprocess_with_path(&args.circuit_name, circuit_dir, &compiled_program.circuit)?;
 
-    Ok(circuit_path)
+    println!("Generated ACIR code into {}", circuit_path.display());
+    Ok(())
 }
 
 pub(crate) fn compile_circuit<P: AsRef<Path>>(
     program_dir: P,
     show_ssa: bool,
     allow_warnings: bool,
 ) -> Result<noirc_driver::CompiledProgram, CliError> {
-    let backend = crate::backends::ConcreteBackend;
-    let mut driver = Resolver::resolve_root_config(program_dir.as_ref(), backend.np_language())?;
-    add_std_lib(&mut driver);
+    let mut driver = setup_driver(program_dir)?;
+    driver.compile_main(show_ssa, allow_warnings, true).map_err(|_| CliError::CompilationError)
+}
 
-    driver.into_compiled_program(show_ssa, allow_warnings).map_err(|_| CliError::CompilationError)
+fn check_crate(program_dir: impl AsRef<Path>, allow_warnings: bool) -> Result<Driver, CliError> {
+    let mut driver = setup_driver(program_dir)?;
+    driver.check_crate(allow_warnings).map_err(|_| CliError::CompilationError)?;
+    Ok(driver)
 }
 
 fn preprocess_with_path<P: AsRef<Path>>(

crates/nargo/src/cli/test_cmd.rs

@@ -93,7 +93,7 @@ fn run_test(
     let backend = crate::backends::ConcreteBackend;
 
     let program = driver
-        .compile_no_check(false, allow_warnings, Some(main), show_output)
+        .compile_no_check(false, allow_warnings, main, show_output)
         .map_err(|_| CliError::Generic(format!("Test '{test_name}' failed to compile")))?;
 
     let mut solved_witness = BTreeMap::new();

crates/nargo/tests/test_data/contracts/Nargo.toml

@@ -0,0 +1,5 @@
+[package]
+authors = [""]
+compiler_version = "0.1"
+
+[dependencies]

crates/nargo/tests/test_data/contracts/Prover.toml

@@ -0,0 +1,2 @@
+x = 3
+y = 2

crates/nargo/tests/test_data/contracts/src/main.nr

@@ -0,0 +1,8 @@
+fn main(x : Field, y : pub Field) {
+    constrain Foo::double(x) == Foo::triple(y);
+}
+
+contract Foo {
+    fn double(x: Field) -> Field { x * 2 }
+    fn triple(x: Field) -> Field { x * 3 }
+}

crates/noirc_driver/src/lib.rs

@@ -8,7 +8,7 @@ use noirc_abi::FunctionSignature;
 use noirc_errors::{reporter, ReportedError};
 use noirc_evaluator::create_circuit;
 use noirc_frontend::graph::{CrateId, CrateName, CrateType, LOCAL_CRATE};
-use noirc_frontend::hir::def_map::CrateDefMap;
+use noirc_frontend::hir::def_map::{Contract, CrateDefMap};
 use noirc_frontend::hir::Context;
 use noirc_frontend::monomorphization::monomorphize;
 use noirc_frontend::node_interner::FuncId;
@@ -34,8 +34,7 @@ impl Driver {
     pub fn compile_file(root_file: PathBuf, np_language: acvm::Language) -> CompiledProgram {
         let mut driver = Driver::new(&np_language);
         driver.create_local_crate(root_file, CrateType::Binary);
-
-        driver.into_compiled_program(false, false).unwrap_or_else(|_| std::process::exit(1))
+        driver.compile_main(false, false, true).unwrap_or_else(|_| std::process::exit(1))
     }
 
     /// Compiles a file and returns true if compilation was successful
@@ -139,13 +138,34 @@ impl Driver {
         Some(func_meta.into_function_signature(&self.context.def_interner))
     }
 
-    pub fn into_compiled_program(
-        mut self,
+    /// Run the frontend to check the crate for errors then compile the main function if there were none
+    pub fn compile_main(
+        &mut self,
         show_ssa: bool,
         allow_warnings: bool,
+        show_output: bool,
     ) -> Result<CompiledProgram, ReportedError> {
         self.check_crate(allow_warnings)?;
-        self.compile_no_check(show_ssa, allow_warnings, None, true)
+        let main = self.main_function();
+        self.compile_no_check(show_ssa, allow_warnings, main, show_output)
+    }
+
+    /// Returns the FuncId of the 'main' funciton.
+    /// - Expects check_crate to be called beforehand
+    /// - Panics if no main function is found
+    pub fn main_function(&self) -> FuncId {
+        // Find the local crate, one should always be present
+        let local_crate = self.context.def_map(LOCAL_CRATE).unwrap();
+
+        // Check the crate type
+        // We don't panic here to allow users to `evaluate` libraries which will do nothing
+        if self.context.crate_graph[LOCAL_CRATE].crate_type != CrateType::Binary {
+            println!("cannot compile crate into a program as the local crate is not a binary. For libraries, please use the check command");
+            std::process::exit(1);
+        };
+
+        // All Binaries should have a main function
+        local_crate.main_function().expect("cannot compile a program with no main function")
     }
 
     /// Compile the current crate. Assumes self.check_crate is called beforehand!
@@ -155,25 +175,9 @@ impl Driver {
         show_ssa: bool,
         allow_warnings: bool,
         // Optional override to provide a different `main` function to start execution
-        main_function: Option<FuncId>,
+        main_function: FuncId,
         show_output: bool,
     ) -> Result<CompiledProgram, ReportedError> {
-        // Find the local crate, one should always be present
-        let local_crate = self.context.def_map(LOCAL_CRATE).unwrap();
-
-        // If no override for the `main` function has been provided, attempt to find it.
-        let main_function = main_function.unwrap_or_else(|| {
-            // Check the crate type
-            // We don't panic here to allow users to `evaluate` libraries which will do nothing
-            if self.context.crate_graph[LOCAL_CRATE].crate_type != CrateType::Binary {
-                println!("cannot compile crate into a program as the local crate is not a binary. For libraries, please use the check command");
-                std::process::exit(1);
-            };
-
-            // All Binaries should have a main function
-            local_crate.main_function().expect("cannot compile a program with no main function")
-        });
-
         let program = monomorphize(main_function, &self.context.def_interner);
 
         let np_language = self.language.clone();
@@ -206,6 +210,14 @@ impl Driver {
             .collect()
     }
 
+    /// Return a Vec of all `contract` declarations in the source code and the functions they contain
+    pub fn get_all_contracts(&self) -> Vec<Contract> {
+        self.context
+            .def_map(LOCAL_CRATE)
+            .expect("The local crate should be analyzed already")
+            .get_all_contracts()
+    }
+
     pub fn function_name(&self, id: FuncId) -> &str {
         self.context.def_interner.function_name(&id)
     }

crates/noirc_driver/src/main.rs

@@ -18,5 +18,5 @@ fn main() {
     driver.add_dep(LOCAL_CRATE, crate_id1, "coo4");
     driver.add_dep(LOCAL_CRATE, crate_id2, "coo3");
 
-    driver.into_compiled_program(false, false).ok();
+    driver.compile_main(false, false, true).ok();
 }

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

@@ -161,7 +161,7 @@ impl<'a> ModCollector<'a> {
             let name = struct_definition.name.clone();
 
             // Create the corresponding module for the struct namespace
-            let id = match self.push_child_module(&name, self.file_id, false, errors) {
+            let id = match self.push_child_module(&name, self.file_id, false, false, errors) {
                 Some(local_id) => StructId(ModuleId { krate, local_id }),
                 None => continue,
             };
@@ -195,7 +195,13 @@ impl<'a> ModCollector<'a> {
         errors: &mut Vec<FileDiagnostic>,
     ) {
         for submodule in submodules {
-            if let Some(child) = self.push_child_module(&submodule.name, file_id, true, errors) {
+            if let Some(child) = self.push_child_module(
+                &submodule.name,
+                file_id,
+                true,
+                submodule.is_contract,
+                errors,
+            ) {
                 collect_defs(
                     self.def_collector,
                     submodule.contents,
@@ -234,7 +240,9 @@ impl<'a> ModCollector<'a> {
         let ast = parse_file(&mut context.file_manager, child_file_id, errors);
 
         // Add module into def collector and get a ModuleId
-        if let Some(child_mod_id) = self.push_child_module(mod_name, child_file_id, true, errors) {
+        if let Some(child_mod_id) =
+            self.push_child_module(mod_name, child_file_id, true, false, errors)
+        {
             collect_defs(
                 self.def_collector,
                 ast,
@@ -254,21 +262,15 @@ impl<'a> ModCollector<'a> {
         mod_name: &Ident,
         file_id: FileId,
         add_to_parent_scope: bool,
+        is_contract: bool,
         errors: &mut Vec<FileDiagnostic>,
     ) -> Option<LocalModuleId> {
-        // Create a new default module
-        let module_id = self.def_collector.def_map.modules.insert(ModuleData::default());
+        let parent = Some(self.module_id);
+        let new_module = ModuleData::new(parent, ModuleOrigin::File(file_id), is_contract);
+        let module_id = self.def_collector.def_map.modules.insert(new_module);
 
         let modules = &mut self.def_collector.def_map.modules;
 
-        // Update the child module to reference the parent
-        modules[module_id].parent = Some(self.module_id);
-
-        // Update the origin of the child module
-        // Also note that the FileId is where this module is defined and not declared
-        // To find out where the module was declared, you need to check its parent
-        modules[module_id].origin = ModuleOrigin::File(file_id);
-
         // Update the parent module to reference the child
         modules[self.module_id.0].children.insert(mod_name.clone(), LocalModuleId(module_id));
 

crates/noirc_frontend/src/hir/def_map/mod.rs

@@ -72,10 +72,8 @@ impl CrateDefMap {
 
         // Allocate a default Module for the root, giving it a ModuleId
         let mut modules: Arena<ModuleData> = Arena::default();
-        let root = modules.insert(ModuleData::default());
-
-        // Set the origin of the root module
-        modules[root].origin = ModuleOrigin::CrateRoot(root_file_id);
+        let origin = ModuleOrigin::CrateRoot(root_file_id);
+        let root = modules.insert(ModuleData::new(None, origin, false));
 
         let def_map = CrateDefMap {
             root: LocalModuleId(root),
@@ -129,6 +127,60 @@ impl CrateDefMap {
             functions.filter(|id| interner.function_meta(id).attributes == Some(Attribute::Test))
         })
     }
+
+    /// Go through all modules in this crate, find all `contract ... { ... }` declarations,
+    /// and collect them all into a Vec.
+    pub fn get_all_contracts(&self) -> Vec<Contract> {
+        self.modules
+            .iter()
+            .filter_map(|(id, module)| {
+                if module.is_contract {
+                    let functions = module
+                        .scope
+                        .values()
+                        .values()
+                        .filter_map(|(id, _)| id.as_function())
+                        .collect();
+
+                    let name = self.get_module_path(id, module.parent);
+                    Some(Contract { name, functions })
+                } else {
+                    None
+                }
+            })
+            .collect()
+    }
+
+    /// Find a child module's name by inspecting its parent.
+    /// Currently required as modules do not store their own names.
+    fn get_module_path(&self, child_id: Index, parent: Option<LocalModuleId>) -> String {
+        if let Some(id) = parent {
+            let parent = &self.modules[id.0];
+            let name = parent
+                .children
+                .iter()
+                .find(|(_, id)| id.0 == child_id)
+                .map(|(name, _)| &name.0.contents)
+                .expect("Child module was not a child of the given parent module");
+
+            let parent_name = self.get_module_path(id.0, parent.parent);
+            if parent_name.is_empty() {
+                name.to_string()
+            } else {
+                format!("{parent_name}.{name}")
+            }
+        } else {
+            String::new()
+        }
+    }
+}
+
+/// A 'contract' in Noir source code with the given name and functions.
+/// This is not an AST node, it is just a convenient form to return for CrateDefMap::get_all_contracts.
+pub struct Contract {
+    /// To keep `name` semi-unique, it is prefixed with the names of parent modules via CrateDefMap::get_module_path
+    pub name: String,
+    pub functions: Vec<FuncId>,
 }
 
 /// Given a FileId, fetch the File, from the FileManager and parse it's content