type_inferencer: check defined identifiers during inference

nac3core/src/codegen/test.rs

@@ -77,6 +77,7 @@ fn test_primitives() {
     };
     let mut virtual_checks = Vec::new();
     let mut calls = HashMap::new();
+    let mut identifiers = vec!["a".to_string(), "b".to_string()];
     let mut inferencer = Inferencer {
         top_level: &top_level,
         function_data: &mut function_data,
@@ -85,6 +86,7 @@ fn test_primitives() {
         primitives: &primitives,
         virtual_checks: &mut virtual_checks,
         calls: &mut calls,
+        defined_identifiers: identifiers.clone()
     };
     inferencer.variable_mapping.insert("a".into(), inferencer.primitives.int32);
     inferencer.variable_mapping.insert("b".into(), inferencer.primitives.int32);
@@ -95,7 +97,6 @@ fn test_primitives() {
         .collect::<Result<Vec<_>, _>>()
         .unwrap();
 
-    let mut identifiers = vec!["a".to_string(), "b".to_string()];
     inferencer.check_block(&statements, &mut identifiers).unwrap();
     let top_level = Arc::new(TopLevelContext {
         definitions: Arc::new(RwLock::new(std::mem::take(&mut *top_level.definitions.write()))),
@@ -235,6 +236,7 @@ fn test_simple_call() {
     };
     let mut virtual_checks = Vec::new();
     let mut calls = HashMap::new();
+    let mut identifiers = vec!["a".to_string(), "foo".into()];
     let mut inferencer = Inferencer {
         top_level: &top_level,
         function_data: &mut function_data,
@@ -243,6 +245,7 @@ fn test_simple_call() {
         primitives: &primitives,
         virtual_checks: &mut virtual_checks,
         calls: &mut calls,
+        defined_identifiers: identifiers.clone()
     };
     inferencer.variable_mapping.insert("a".into(), inferencer.primitives.int32);
     inferencer.variable_mapping.insert("foo".into(), fun_ty);
@@ -273,7 +276,6 @@ fn test_simple_call() {
         unreachable!()
     }
 
-    let mut identifiers = vec!["a".to_string(), "foo".into()];
     inferencer.check_block(&statements_1, &mut identifiers).unwrap();
     let top_level = Arc::new(TopLevelContext {
         definitions: Arc::new(RwLock::new(std::mem::take(&mut *top_level.definitions.write()))),

nac3core/src/typecheck/function_check.rs

@@ -42,7 +42,7 @@ impl<'a> Inferencer<'a> {
     fn check_expr(
         &mut self,
         expr: &Expr<Option<Type>>,
-        defined_identifiers: &[String],
+        defined_identifiers: &mut Vec<String>,
     ) -> Result<(), String> {
         // there are some cases where the custom field is None
         if let Some(ty) = &expr.custom {
@@ -57,12 +57,16 @@ impl<'a> Inferencer<'a> {
         match &expr.node {
             ExprKind::Name { id, .. } => {
                 if !defined_identifiers.contains(id) {
+                    if self.function_data.resolver.get_identifier_def(id).is_some() {
+                        defined_identifiers.push(id.clone());
+                    } else {
                         return Err(format!(
                             "unknown identifier {} (use before def?) at {}",
                             id, expr.location
                         ));
                     }
                 }
+            }
             ExprKind::List { elts, .. }
             | ExprKind::Tuple { elts, .. }
             | ExprKind::BoolOp { values: elts, .. } => {
@@ -106,7 +110,7 @@ impl<'a> Inferencer<'a> {
                         defined_identifiers.push(arg.node.arg.clone());
                     }
                 }
-                self.check_expr(body, &defined_identifiers)?;
+                self.check_expr(body, &mut defined_identifiers)?;
             }
             ExprKind::ListComp { elt, generators, .. } => {
                 // in our type inference stage, we already make sure that there is only 1 generator
@@ -115,7 +119,7 @@ impl<'a> Inferencer<'a> {
                 let mut defined_identifiers = defined_identifiers.to_vec();
                 self.check_pattern(target, &mut defined_identifiers)?;
                 for term in once(elt.as_ref()).chain(ifs.iter()) {
-                    self.check_expr(term, &defined_identifiers)?;
+                    self.check_expr(term, &mut defined_identifiers)?;
                 }
             }
             ExprKind::Call { func, args, keywords } => {

nac3core/src/typecheck/type_inferencer/mod.rs

@@ -45,6 +45,7 @@ pub struct FunctionData {
 
 pub struct Inferencer<'a> {
     pub top_level: &'a TopLevelContext,
+    pub defined_identifiers: Vec<String>,
     pub function_data: &'a mut FunctionData,
     pub unifier: &'a mut Unifier,
     pub primitives: &'a PrimitiveStore,
@@ -74,13 +75,14 @@ impl<'a> fold::Fold<()> for Inferencer<'a> {
         let stmt = match node.node {
             // we don't want fold over type annotation
             ast::StmtKind::AnnAssign { target, annotation, value, simple } => {
+                self.infer_pattern(&target)?;
                 let target = Box::new(self.fold_expr(*target)?);
                 let value = if let Some(v) = value {
                     let ty = Box::new(self.fold_expr(*v)?);
                     self.unify(target.custom.unwrap(), ty.custom.unwrap(), &node.location)?;
                     Some(ty)
                 } else {
-                    None
+                    return Err(format!("declaration without definition is not yet supported, at {}", node.location))
                 };
                 let top_level_defs = self.top_level.definitions.read();
                 let annotation_type = self.function_data.resolver.parse_type_annotation(
@@ -97,6 +99,16 @@ impl<'a> fold::Fold<()> for Inferencer<'a> {
                     node: ast::StmtKind::AnnAssign { target, annotation, value, simple },
                 }
             }
+            ast::StmtKind::For { ref target, .. } => {
+                self.infer_pattern(target)?;
+                fold::fold_stmt(self, node)?
+            }
+            ast::StmtKind::Assign { ref targets, .. } => {
+                for target in targets {
+                    self.infer_pattern(target)?;
+                }
+                fold::fold_stmt(self, node)?
+            }
             _ => fold::fold_stmt(self, node)?,
         };
         match &stmt.node {
@@ -146,7 +158,19 @@ impl<'a> fold::Fold<()> for Inferencer<'a> {
         };
         let custom = match &expr.node {
             ast::ExprKind::Constant { value, .. } => Some(self.infer_constant(value)?),
-            ast::ExprKind::Name { id, .. } => Some(self.infer_identifier(id)?),
+            ast::ExprKind::Name { id, .. } => {
+                if !self.defined_identifiers.contains(id) {
+                    if self.function_data.resolver.get_identifier_def(id.as_str()).is_some() {
+                        self.defined_identifiers.push(id.clone());
+                    } else {
+                        return Err(format!(
+                            "unknown identifier {} (use before def?) at {}",
+                            id, expr.location
+                        ));
+                    }
+                }
+                Some(self.infer_identifier(id)?)
+            }
             ast::ExprKind::List { elts, .. } => Some(self.infer_list(elts)?),
             ast::ExprKind::Tuple { elts, .. } => Some(self.infer_tuple(elts)?),
             ast::ExprKind::Attribute { value, attr, ctx: _ } => {
@@ -187,6 +211,24 @@ impl<'a> Inferencer<'a> {
         self.unifier.unify(a, b).map_err(|old| format!("{} at {}", old, location))
     }
 
+    fn infer_pattern(&mut self, pattern: &ast::Expr<()>) -> Result<(), String> {
+        match &pattern.node {
+            ExprKind::Name { id, .. } => {
+                if !self.defined_identifiers.contains(id) {
+                    self.defined_identifiers.push(id.clone());
+                }
+                Ok(())
+            }
+            ExprKind::Tuple { elts, .. } => {
+                for elt in elts.iter() {
+                    self.infer_pattern(elt)?;
+                }
+                Ok(())
+            }
+            _ => Ok(()),
+        }
+    }
+
     fn build_method_call(
         &mut self,
         location: Location,
@@ -228,6 +270,13 @@ impl<'a> Inferencer<'a> {
             );
         }
 
+        let mut defined_identifiers = self.defined_identifiers.clone();
+        for arg in args.args.iter() {
+            let name = &arg.node.arg;
+            if !defined_identifiers.contains(name) {
+                defined_identifiers.push(name.clone());
+            }
+        }
         let fn_args: Vec<_> = args
             .args
             .iter()
@@ -236,6 +285,7 @@ impl<'a> Inferencer<'a> {
         let mut variable_mapping = self.variable_mapping.clone();
         variable_mapping.extend(fn_args.iter().cloned());
         let ret = self.unifier.get_fresh_var().0;
+
         let mut new_context = Inferencer {
             function_data: self.function_data,
             unifier: self.unifier,
@@ -243,6 +293,7 @@ impl<'a> Inferencer<'a> {
             virtual_checks: self.virtual_checks,
             calls: self.calls,
             top_level: self.top_level,
+            defined_identifiers,
             variable_mapping,
         };
         let fun = FunSignature {
@@ -279,6 +330,7 @@ impl<'a> Inferencer<'a> {
             );
         }
         let variable_mapping = self.variable_mapping.clone();
+        let defined_identifiers = self.defined_identifiers.clone();
         let mut new_context = Inferencer {
             function_data: self.function_data,
             unifier: self.unifier,
@@ -287,12 +339,14 @@ impl<'a> Inferencer<'a> {
             variable_mapping,
             primitives: self.primitives,
             calls: self.calls,
+            defined_identifiers,
         };
-        let elt = new_context.fold_expr(elt)?;
         let generator = generators.pop().unwrap();
         if generator.is_async {
             return Err("Async iterator not supported.".to_string());
         }
+        new_context.infer_pattern(&generator.target)?;
+        let elt = new_context.fold_expr(elt)?;
         let target = new_context.fold_expr(*generator.target)?;
         let iter = new_context.fold_expr(*generator.iter)?;
         let ifs: Vec<_> = generator

nac3core/src/typecheck/type_inferencer/test.rs

@@ -313,6 +313,7 @@ impl TestEnvironment {
             primitives: &mut self.primitives,
             virtual_checks: &mut self.virtual_checks,
             calls: &mut self.calls,
+            defined_identifiers: vec![]
         }
     }
 }
@@ -382,6 +383,7 @@ fn test_basic(source: &str, mapping: HashMap<&str, &str>, virtuals: &[(&str, &st
     let mut defined_identifiers: Vec<_> = env.identifier_mapping.keys().cloned().collect();
     defined_identifiers.push("virtual".to_string());
     let mut inferencer = env.get_inferencer();
+    inferencer.defined_identifiers = defined_identifiers.clone();
     let statements = parse_program(source).unwrap();
     let statements = statements
         .into_iter()
@@ -523,6 +525,7 @@ fn test_primitive_magic_methods(source: &str, mapping: HashMap<&str, &str>) {
     let mut defined_identifiers: Vec<_> = env.identifier_mapping.keys().cloned().collect();
     defined_identifiers.push("virtual".to_string());
     let mut inferencer = env.get_inferencer();
+    inferencer.defined_identifiers = defined_identifiers.clone();
     let statements = parse_program(source).unwrap();
     let statements = statements
         .into_iter()

nac3standalone/src/main.rs

@@ -112,6 +112,7 @@ fn main() {
         primitives: &primitives,
         virtual_checks: &mut virtual_checks,
         calls: &mut calls,
+        defined_identifiers: vec![]
     };
 
     let statements = statements
@@ -124,6 +125,7 @@ fn main() {
     inferencer
         .check_block(&statements, &mut identifiers)
         .unwrap();
+
     let top_level = Arc::new(TopLevelContext {
         definitions: Arc::new(RwLock::new(std::mem::take(
             &mut *top_level.definitions.write(),