From ebd25af38b5d61b41245e5a33404d8263b8b9b83 Mon Sep 17 00:00:00 2001
From: z78078 <cc@m-labs.hk>
Date: Thu, 7 Jul 2022 10:36:25 +0800
Subject: [PATCH] nac3standalone: allow classes without explicit init (#221)

Reviewed-on: https://git.m-labs.hk/M-Labs/nac3/pulls/304
Co-authored-by: z78078 <cc@m-labs.hk>
Co-committed-by: z78078 <cc@m-labs.hk>
---
 nac3artiq/src/lib.rs              |  4 ++--
 nac3core/src/toplevel/composer.rs |  3 ++-
 nac3core/src/toplevel/test.rs     | 26 +++++++++++++++++++++-----
 nac3standalone/src/main.rs        |  2 +-
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/nac3artiq/src/lib.rs b/nac3artiq/src/lib.rs
index 855b1331..1a58bb7e 100644
--- a/nac3artiq/src/lib.rs
+++ b/nac3artiq/src/lib.rs
@@ -371,7 +371,7 @@ impl Nac3 {
                 });
 
             let (name, def_id, ty) = composer
-                .register_top_level(stmt.clone(), Some(resolver.clone()), path.clone())
+                .register_top_level(stmt.clone(), Some(resolver.clone()), path.clone(), false)
                 .map_err(|e| {
                     CompileError::new_err(format!(
                         "compilation failed\n----------\n{}",
@@ -451,7 +451,7 @@ impl Nac3 {
         });
         let resolver = Arc::new(Resolver(inner_resolver.clone())) as Arc<dyn SymbolResolver + Send + Sync>;
         let (_, def_id, _) = composer
-            .register_top_level(synthesized.pop().unwrap(), Some(resolver.clone()), "".into())
+            .register_top_level(synthesized.pop().unwrap(), Some(resolver.clone()), "".into(), false)
             .unwrap();
 
         let fun_signature =
diff --git a/nac3core/src/toplevel/composer.rs b/nac3core/src/toplevel/composer.rs
index 0feb4622..16f508a7 100644
--- a/nac3core/src/toplevel/composer.rs
+++ b/nac3core/src/toplevel/composer.rs
@@ -164,6 +164,7 @@ impl TopLevelComposer {
         ast: ast::Stmt<()>,
         resolver: Option<Arc<dyn SymbolResolver + Send + Sync>>,
         mod_path: String,
+        allow_no_constructor: bool,
     ) -> Result<(StrRef, DefinitionId, Option<Type>), String> {
         let defined_names = &mut self.defined_names;
         match &ast.node {
@@ -298,7 +299,7 @@ impl TopLevelComposer {
                     self.definition_ast_list.push((def, Some(ast)));
                 }
 
-                let result_ty = if contains_constructor { Some(constructor_ty) } else { None };
+                let result_ty = if allow_no_constructor || contains_constructor { Some(constructor_ty) } else { None };
                 Ok((class_name, DefinitionId(class_def_id), result_ty))
             }
 
diff --git a/nac3core/src/toplevel/test.rs b/nac3core/src/toplevel/test.rs
index e74c21db..49400711 100644
--- a/nac3core/src/toplevel/test.rs
+++ b/nac3core/src/toplevel/test.rs
@@ -105,7 +105,7 @@ impl SymbolResolver for Resolver {
                 def __init__(self):
                     self.c: int32 = 4
                     self.a: bool = True
-        "}
+        "},
     ];
     "register"
 )]
@@ -116,10 +116,26 @@ fn test_simple_register(source: Vec<&str>) {
         let ast = parse_program(s, Default::default()).unwrap();
         let ast = ast[0].clone();
 
-        composer.register_top_level(ast, None, "".into()).unwrap();
+        composer.register_top_level(ast, None, "".into(), false).unwrap();
     }
 }
 
+#[test_case(
+    indoc! {"
+        class A:
+            def foo(self):
+                pass
+        a = A()
+    "};
+    "register"
+)]
+fn test_simple_register_without_constructor(source: &str) {
+    let mut composer: TopLevelComposer = Default::default();
+    let ast = parse_program(source, Default::default()).unwrap();
+    let ast = ast[0].clone();
+    composer.register_top_level(ast, None, "".into(), true).unwrap();
+}
+
 #[test_case(
     vec![
         indoc! {"
@@ -163,7 +179,7 @@ fn test_simple_function_analyze(source: Vec<&str>, tys: Vec<&str>, names: Vec<&s
         let ast = ast[0].clone();
 
         let (id, def_id, ty) =
-            composer.register_top_level(ast, Some(resolver.clone()), "".into()).unwrap();
+            composer.register_top_level(ast, Some(resolver.clone()), "".into(), false).unwrap();
         internal_resolver.add_id_def(id, def_id);
         if let Some(ty) = ty {
             internal_resolver.add_id_type(id, ty);
@@ -515,7 +531,7 @@ fn test_analyze(source: Vec<&str>, res: Vec<&str>) {
         let ast = ast[0].clone();
 
         let (id, def_id, ty) = {
-            match composer.register_top_level(ast, Some(resolver.clone()), "".into()) {
+            match composer.register_top_level(ast, Some(resolver.clone()), "".into(), false) {
                 Ok(x) => x,
                 Err(msg) => {
                     if print {
@@ -699,7 +715,7 @@ fn test_inference(source: Vec<&str>, res: Vec<&str>) {
         let ast = ast[0].clone();
 
         let (id, def_id, ty) = {
-            match composer.register_top_level(ast, Some(resolver.clone()), "".into()) {
+            match composer.register_top_level(ast, Some(resolver.clone()), "".into(), false) {
                 Ok(x) => x,
                 Err(msg) => {
                     if print {
diff --git a/nac3standalone/src/main.rs b/nac3standalone/src/main.rs
index 3d93d1da..cc50fb63 100644
--- a/nac3standalone/src/main.rs
+++ b/nac3standalone/src/main.rs
@@ -208,7 +208,7 @@ fn main() {
                 if module == &Some("__future__".into()) && names.len() == 1 && names[0].name == "annotations".into() => (),
             _ => {
                 let (name, def_id, ty) =
-                    composer.register_top_level(stmt, Some(resolver.clone()), "__main__".into()).unwrap();
+                    composer.register_top_level(stmt, Some(resolver.clone()), "__main__".into(), true).unwrap();
                 internal_resolver.add_id_def(name, def_id);
                 if let Some(ty) = ty {
                     internal_resolver.add_id_type(name, ty);