Handle polymorphism with virtual tables

flake.nix

@@ -180,7 +180,9 @@
           clippy
           pre-commit
           rustfmt
+          rust-analyzer
         ];
+        RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
         shellHook =
           ''
           export DEMO_LINALG_STUB=${packages.x86_64-linux.demo-linalg-stub}/lib/liblinalg.a

nac3core/src/codegen/expr.rs

@@ -2982,6 +2982,29 @@ pub fn gen_expr<'ctx, G: CodeGenerator>(
             }
         }
         ExprKind::Call { func, args, keywords } => {
+            // Check if call is to a parent method
+            let mut is_override = false;
+            if let Some(arg) = args.last() {
+                if let ExprKind::Name { id, .. } = arg.node {
+                    if id == "self".into() {
+                        is_override = true;
+                    }
+                }
+            }
+
+            let mut args = args.clone();
+            let (zelf, func_id) = if is_override {
+                let zelf = args.pop();
+                let ExprKind::Constant { value: ast::Constant::Int(func_id), .. } =
+                    args.pop().unwrap().node
+                else {
+                    unreachable!()
+                };
+                (zelf, Some(func_id))
+            } else {
+                (None, None)
+            };
+
             let mut params = args
                 .iter()
                 .map(|arg| generator.gen_expr(ctx, arg))
@@ -3025,14 +3048,21 @@ pub fn gen_expr<'ctx, G: CodeGenerator>(
                     let Some(val) = generator.gen_expr(ctx, value)? else { return Ok(None) };
 
                     // Handle Class Method calls
-                    let id = if let TypeEnum::TObj { obj_id, .. } =
+                    let class_ty = if is_override {
-                        &*ctx.unifier.get_ty(value.custom.unwrap())
+                        zelf.unwrap().custom.unwrap()
-                    {
+                    } else {
+                        value.custom.unwrap()
+                    };
+                    let id = if let TypeEnum::TObj { obj_id, .. } = &*ctx.unifier.get_ty(class_ty) {
                         *obj_id
                     } else {
                         unreachable!()
                     };
-                    let fun_id = {
+
+                    // Get function definition
+                    let fun_id = if is_override {
+                        DefinitionId(func_id.unwrap() as usize)
+                    } else {
                         let defs = ctx.top_level.definitions.read();
                         let obj_def = defs.get(id.0).unwrap().read();
                         let TopLevelDef::Class { methods, .. } = &*obj_def else { unreachable!() };

nac3core/src/toplevel/composer.rs

@@ -23,7 +23,7 @@ impl Default for ComposerConfig {
     }
 }
 
-type DefAst = (Arc<RwLock<TopLevelDef>>, Option<Stmt<()>>);
+pub type DefAst = (Arc<RwLock<TopLevelDef>>, Option<Stmt<()>>);
 pub struct TopLevelComposer {
     // list of top level definitions, same as top level context
     pub definition_ast_list: Vec<DefAst>,
@@ -1822,7 +1822,11 @@ impl TopLevelComposer {
                         if *name != init_str_id {
                             unreachable!("must be init function here")
                         }
-                        let all_inited = Self::get_all_assigned_field(body.as_slice())?;
+                        let all_inited = Self::get_all_assigned_field(
+                            class_name.to_string().into(),
+                            definition_ast_list,
+                            body.as_slice(),
+                        )?;
                         for (f, _, _) in fields {
                             if !all_inited.contains(f) {
                                 return Err(HashSet::from([

nac3core/src/toplevel/helper.rs

@@ -3,6 +3,7 @@ use std::convert::TryInto;
 use crate::symbol_resolver::SymbolValue;
 use crate::toplevel::numpy::unpack_ndarray_var_tys;
 use crate::typecheck::typedef::{into_var_map, iter_type_vars, Mapping, TypeVarId, VarMap};
+use ast::ExprKind;
 use nac3parser::ast::{Constant, Location};
 use strum::IntoEnumIterator;
 use strum_macros::EnumIter;
@@ -733,7 +734,12 @@ impl TopLevelComposer {
         )
     }
 
-    pub fn get_all_assigned_field(stmts: &[Stmt<()>]) -> Result<HashSet<StrRef>, HashSet<String>> {
+    #[allow(clippy::only_used_in_recursion)]
+    pub fn get_all_assigned_field(
+        class_name: StrRef,
+        ast: &Vec<DefAst>,
+        stmts: &[Stmt<()>],
+    ) -> Result<HashSet<StrRef>, HashSet<String>> {
         let mut result = HashSet::new();
         for s in stmts {
             match &s.node {
@@ -769,30 +775,77 @@ impl TopLevelComposer {
                 // TODO: do not check for For and While?
                 ast::StmtKind::For { body, orelse, .. }
                 | ast::StmtKind::While { body, orelse, .. } => {
-                    result.extend(Self::get_all_assigned_field(body.as_slice())?);
+                    result.extend(Self::get_all_assigned_field(class_name, ast, body.as_slice())?);
-                    result.extend(Self::get_all_assigned_field(orelse.as_slice())?);
+                    result.extend(Self::get_all_assigned_field(
+                        class_name,
+                        ast,
+                        orelse.as_slice(),
+                    )?);
                 }
                 ast::StmtKind::If { body, orelse, .. } => {
-                    let inited_for_sure = Self::get_all_assigned_field(body.as_slice())?
+                    let inited_for_sure =
-                        .intersection(&Self::get_all_assigned_field(orelse.as_slice())?)
+                        Self::get_all_assigned_field(class_name, ast, body.as_slice())?
+                            .intersection(&Self::get_all_assigned_field(
+                                class_name,
+                                ast,
+                                orelse.as_slice(),
+                            )?)
                             .copied()
                             .collect::<HashSet<_>>();
                     result.extend(inited_for_sure);
                 }
                 ast::StmtKind::Try { body, orelse, finalbody, .. } => {
-                    let inited_for_sure = Self::get_all_assigned_field(body.as_slice())?
+                    let inited_for_sure =
-                        .intersection(&Self::get_all_assigned_field(orelse.as_slice())?)
+                        Self::get_all_assigned_field(class_name, ast, body.as_slice())?
+                            .intersection(&Self::get_all_assigned_field(
+                                class_name,
+                                ast,
+                                orelse.as_slice(),
+                            )?)
                             .copied()
                             .collect::<HashSet<_>>();
                     result.extend(inited_for_sure);
-                    result.extend(Self::get_all_assigned_field(finalbody.as_slice())?);
+                    result.extend(Self::get_all_assigned_field(
+                        class_name,
+                        ast,
+                        finalbody.as_slice(),
+                    )?);
                 }
                 ast::StmtKind::With { body, .. } => {
-                    result.extend(Self::get_all_assigned_field(body.as_slice())?);
+                    result.extend(Self::get_all_assigned_field(class_name, ast, body.as_slice())?);
+                }
+                // Variables Initiated in function calls
+                ast::StmtKind::Expr { value, .. } => {
+                    let ExprKind::Call { func, .. } = &value.node else {
+                        continue;
+                    };
+                    let ExprKind::Attribute { value, attr, .. } = &func.node else {
+                        continue;
+                    };
+                    let ExprKind::Name { id, .. } = &value.node else {
+                        continue;
+                    };
+                    // Need to conside the two cases:
+                    //  Case 1) Call to class function i.e. id = `self`
+                    //  Case 2) Call to class ancestor function i.e. id = ancestor_name
+                    // We leave checking whether ancestor is called to type checker
+                    // if *id == "self".into() {
+                    //     ast.iter().find_map(|def| {
+                    //         let Some(ast::Located {
+                    //             node: ast::StmtKind::ClassDef { name, body, .. },
+                    //             ..
+                    //         }) = def.1
+                    //         else {
+                    //             return None;
+                    //         };
+                    //         if *name == class_name {}
+                    //         None
+                    //     });
+                    // }
                 }
                 ast::StmtKind::Pass { .. }
                 | ast::StmtKind::Assert { .. }
-                | ast::StmtKind::Expr { .. } => {}
+                | ast::StmtKind::AnnAssign { .. } => {}
 
                 _ => {
                     unimplemented!()

nac3core/src/typecheck/type_inferencer/mod.rs

@@ -12,6 +12,7 @@ use super::{
         RecordField, RecordKey, Type, TypeEnum, TypeVar, Unifier, VarMap,
     },
 };
+use crate::toplevel::type_annotation::TypeAnnotation;
 use crate::{
     symbol_resolver::{SymbolResolver, SymbolValue},
     toplevel::{
@@ -1672,6 +1673,91 @@ impl<'a> Inferencer<'a> {
         Ok(None)
     }
 
+    /// Checks whether a class method is calling parent function
+    /// Returns [`None`] if its not a call to parent method, otherwise
+    /// returns a new `func` with class name replaced by `self` and class name store as `ExprKind::Constant`
+    ///
+    /// e.g.  A.f1(self, ...) returns Some(self.f1, Some(ExprKind::Constant(A))
+    #[allow(clippy::type_complexity)]
+    fn check_overriding(
+        &mut self,
+        func: &ast::Expr<()>,
+        args: &[ast::Expr<()>],
+    ) -> Result<Option<(ast::Expr<()>, Option<ast::Expr<Option<Type>>>)>, InferenceError> {
+        // `self` must be first argument for call to parent method
+        if let Some(Located { node: ExprKind::Name { id, .. }, .. }) = &args.first() {
+            if *id != "self".into() {
+                return Ok(None);
+            }
+        } else {
+            return Ok(None);
+        }
+
+        let Located {
+            node: ExprKind::Attribute { value, attr: method_name, ctx }, location, ..
+        } = func
+        else {
+            return Ok(None);
+        };
+        let ExprKind::Name { id: class_name, ctx: class_ctx } = &value.node else {
+            return Ok(None);
+        };
+        let zelf = &self.fold_expr(args[0].clone())?;
+
+        // Check whether the method belongs to class ancestors
+        let def_id = self.unifier.get_ty(zelf.custom.unwrap());
+        let TypeEnum::TObj { obj_id, .. } = def_id.as_ref() else { unreachable!() };
+        let defs = self.top_level.definitions.read();
+        let res = {
+            if let TopLevelDef::Class { ancestors, .. } = &*defs[obj_id.0].read() {
+                let res = ancestors.iter().find_map(|f| {
+                    let TypeAnnotation::CustomClass { id, .. } = f else { unreachable!() };
+                    let TopLevelDef::Class { name, methods, .. } = &*defs[id.0].read() else {
+                        unreachable!()
+                    };
+                    // Class names are stored as `__module__.class`
+                    let name = name.to_string();
+                    let (_, name) = name.split_once('.').unwrap();
+                    if name == class_name.to_string() {
+                        return methods.iter().find_map(|f| {
+                            if f.0 == *method_name {
+                                return Some(ast::Constant::Int(f.2 .0.try_into().unwrap()));
+                            }
+                            None
+                        });
+                    }
+                    None
+                });
+                res
+            } else {
+                None
+            }
+        };
+
+        match res {
+            Some(r) => {
+                let mut new_func = func.clone();
+                let mut new_value = value.clone();
+                new_value.node = ExprKind::Name { id: "self".into(), ctx: *class_ctx };
+                new_func.node =
+                    ExprKind::Attribute { value: new_value, attr: *method_name, ctx: *ctx };
+
+                let dummy_arg = self.fold_expr(Located {
+                    location: *location,
+                    custom: (),
+                    node: ExprKind::Constant::<()> { value: r, kind: None },
+                })?;
+
+                // args.remove (dummy_arg);
+                Ok(Some((new_func, Some(dummy_arg))))
+            }
+            None => report_error(
+                format!("Method {class_name}.{method_name} not found in ancestor list").as_str(),
+                *location,
+            ),
+        }
+    }
+
     fn fold_call(
         &mut self,
         location: Location,
@@ -1685,8 +1771,21 @@ impl<'a> Inferencer<'a> {
             return Ok(spec_call_func);
         }
 
+        let mut zelf = None;
+
+        // Check for call to parent method
+        let override_res = self.check_overriding(&func, &args)?;
+        let is_override = override_res.is_some();
+        let (func, dummy_var) = override_res.unwrap_or((func, None));
+
         let func = Box::new(self.fold_expr(func)?);
-        let args = args.into_iter().map(|v| self.fold_expr(v)).collect::<Result<Vec<_>, _>>()?;
+        let mut args =
+            args.into_iter().map(|v| self.fold_expr(v)).collect::<Result<Vec<_>, _>>()?;
+
+        // Remove self from arguments
+        if is_override {
+            zelf = Some(args.remove(0));
+        }
         let keywords = keywords
             .into_iter()
             .map(|v| fold::fold_keyword(self, v))
@@ -1708,6 +1807,13 @@ impl<'a> Inferencer<'a> {
                 self.unifier.unify_call(&call, func.custom.unwrap(), sign).map_err(|e| {
                     HashSet::from([e.at(Some(location)).to_display(self.unifier).to_string()])
                 })?;
+
+                // Add `class_name` and `self` to arguments for `gen_expr` to generate call to parent method
+                if let Some(mut arg) = zelf {
+                    arg.node = ExprKind::Name { id: "self".into(), ctx: ExprContext::Load };
+                    args.push(dummy_var.unwrap());
+                    args.push(arg);
+                }
                 return Ok(Located {
                     location,
                     custom: Some(sign.ret),

nac3standalone/demo/src/inheritance.py

@@ -7,26 +7,56 @@ def output_int32(x: int32):
 class A:
     a: int32
     
-    def __init__(self, a: int32):
+    def __init__(self, param_a: int32):
-        self.a = a
+        self.a = param_a
     
     def f1(self):
-        self.f2()
+        output_int32(12)
     
     def f2(self):
-        output_int32(self.a)
+        output_int32(124)
 
 class B(A):
     b: int32
     
-    def __init__(self, b: int32):
+    def __init__(self, param_a: int32, param_b: int32):
-        self.a = b + 1
+        self.a = param_a
+        self.b = param_b
+    
+    def f3(self):
+        output_int32(20)
+
+    def f1(self):
+        output_int32(15)
+    
+    def f2(self):
+        self.b = 12
+        A.f1(self)
+    
+class C(B):
+    def __init__(self, a: int32, b: int32):
+        self.a = a
         self.b = b
     
+    def f1(self):
+        output_int32(17)
+    
+    def f3(self):
+        self.a = 2
+        A.f2(self)
+    
+    def f4(self):
+        A.f1(self)
+        B.f2(self)
 
 def run() -> int32:
-    aaa = A(5)
+    c = C(1, 2)
-    bbb = B(2)
+    c.f3()
-    aaa.f1()
+    c.f4()
-    bbb.f1()
+
+    a = A(1)
+
+    output_int32(c.a)
+    output_int32(c.b)
+
     return 0