fix: distinguish between access to class/instance attr

crates/erg_compiler/codegen.rs

@@ -646,8 +646,8 @@ impl PyCodeGenerator {
             }
             StoreLoadKind::Local | StoreLoadKind::LocalConst => match acc_kind {
                 Name => LOAD_NAME as u8,
-                Attr => LOAD_ATTR as u8,
-                Method => LOAD_METHOD as u8,
+                UnboundAttr => LOAD_ATTR as u8,
+                BoundAttr => LOAD_METHOD as u8,
             },
         }
     }
@@ -669,9 +669,9 @@ impl PyCodeGenerator {
             StoreLoadKind::Local | StoreLoadKind::LocalConst => {
                 match acc_kind {
                     Name => STORE_NAME as u8,
-                    Attr => STORE_ATTR as u8,
+                    UnboundAttr => STORE_ATTR as u8,
                     // cannot overwrite methods directly
-                    Method => STORE_ATTR as u8,
+                    BoundAttr => STORE_ATTR as u8,
                 }
             }
         }
@@ -792,9 +792,9 @@ impl PyCodeGenerator {
         log!(info "entered {} ({ident})", fn_name!());
         let escaped = escape_ident(ident);
         let name = self
-            .local_search(&escaped, Attr)
+            .local_search(&escaped, UnboundAttr)
             .unwrap_or_else(|| self.register_attr(escaped));
-        let instr = self.select_load_instr(name.kind, Attr);
+        let instr = self.select_load_instr(name.kind, UnboundAttr);
         self.write_instr(instr);
         self.write_arg(name.idx);
         if self.py_version.minor >= Some(11) {
@@ -809,9 +809,9 @@ impl PyCodeGenerator {
         }
         let escaped = escape_ident(ident);
         let name = self
-            .local_search(&escaped, Method)
+            .local_search(&escaped, BoundAttr)
             .unwrap_or_else(|| self.register_method(escaped));
-        let instr = self.select_load_instr(name.kind, Method);
+        let instr = self.select_load_instr(name.kind, BoundAttr);
         self.write_instr(instr);
         self.write_arg(name.idx);
         if self.py_version.minor >= Some(11) {
@@ -866,7 +866,7 @@ impl PyCodeGenerator {
             }
             Accessor::Attr(attr) => {
                 self.emit_expr(*attr.obj);
-                self.emit_store_instr(attr.ident, Attr);
+                self.emit_store_instr(attr.ident, UnboundAttr);
             }
         }
     }
@@ -1010,7 +1010,7 @@ impl PyCodeGenerator {
             self.emit_precall_and_call(argc);
         } else {
             match kind {
-                AccessKind::Method => self.write_instr(Opcode310::CALL_METHOD),
+                AccessKind::BoundAttr => self.write_instr(Opcode310::CALL_METHOD),
                 _ => self.write_instr(Opcode310::CALL_FUNCTION),
             }
             self.write_arg(argc);
@@ -2188,7 +2188,7 @@ impl PyCodeGenerator {
         let is_py_api = method_name.is_py_api();
         self.emit_expr(obj);
         self.emit_load_method_instr(method_name);
-        self.emit_args_311(args, Method, is_py_api);
+        self.emit_args_311(args, BoundAttr, is_py_api);
     }
 
     fn emit_var_args_311(&mut self, pos_len: usize, var_args: &PosArg) {
@@ -3121,7 +3121,7 @@ impl PyCodeGenerator {
         self.emit_load_name_instr(Identifier::private("#path"));
         self.emit_load_method_instr(Identifier::public("append"));
         self.emit_load_const(erg_std_path().to_str().unwrap());
-        self.emit_call_instr(1, Method);
+        self.emit_call_instr(1, BoundAttr);
         self.stack_dec();
         self.emit_pop_top();
         let erg_std_mod = Identifier::public("_erg_std_prelude");

crates/erg_compiler/compile.rs

@@ -80,19 +80,31 @@ impl Name {
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum AccessKind {
     Name,
-    Attr,
-    Method,
+    /// class/module attr
+    /// e.g. `Str.center`
+    UnboundAttr,
+    /// method/instance attr
+    /// e.g. `"aaa".center`
+    ///
+    /// can also access class/module attrs
+    BoundAttr,
 }
 
 impl AccessKind {
     pub const fn is_local(&self) -> bool {
         matches!(self, Self::Name)
     }
-    pub const fn is_attr(&self) -> bool {
-        matches!(self, Self::Attr)
+    pub const fn is_unbound_attr(&self) -> bool {
+        matches!(self, Self::UnboundAttr)
     }
-    pub const fn is_method(&self) -> bool {
-        matches!(self, Self::Method)
+    pub const fn is_bound_attr(&self) -> bool {
+        matches!(self, Self::BoundAttr)
+    }
+    pub fn matches(&self, vi: &VarInfo) -> bool {
+        match self {
+            Self::Name | Self::BoundAttr => true,
+            Self::UnboundAttr => !vi.kind.is_instance_attr(),
+        }
     }
 }
 

crates/erg_compiler/context/inquire.rs

@@ -420,7 +420,7 @@ impl Context {
     ) -> Triple<VarInfo, TyCheckError> {
         if let Some(vi) = self.get_current_scope_var(&ident.name) {
             match self.validate_visibility(ident, vi, input, namespace) {
-                Ok(()) => {
+                Ok(()) if acc_kind.matches(vi) => {
                     return Triple::Ok(vi.clone());
                 }
                 Err(err) => {
@@ -428,6 +428,7 @@ impl Context {
                         return Triple::Err(err);
                     }
                 }
+                _ => {}
             }
         } else if let Some((name, _vi)) = self
             .future_defined_locals
@@ -453,6 +454,17 @@ impl Context {
                 self.get_similar_name(ident.inspect()),
             ));
         }
+        for (_, method_ctx) in self.methods_list.iter() {
+            match method_ctx.rec_get_var_info(ident, acc_kind, input, namespace) {
+                Triple::Ok(vi) => {
+                    return Triple::Ok(vi);
+                }
+                Triple::Err(e) => {
+                    return Triple::Err(e);
+                }
+                Triple::None => {}
+            }
+        }
         if acc_kind.is_local() {
             if let Some(parent) = self.get_outer().or_else(|| self.get_builtins()) {
                 return parent.rec_get_var_info(ident, acc_kind, input, namespace);
@@ -468,7 +480,7 @@ impl Context {
     ) -> Option<&mut VarInfo> {
         if let Some(vi) = self.get_current_scope_var(&ident.name) {
             match self.validate_visibility(ident, vi, &self.cfg.input, self) {
-                Ok(()) => {
+                Ok(()) if acc_kind.matches(vi) => {
                     let vi = self.get_mut_current_scope_var(&ident.name).unwrap();
                     return Some(vi);
                 }
@@ -477,6 +489,7 @@ impl Context {
                         return None;
                     }
                 }
+                _ => {}
             }
         }
         if acc_kind.is_local() {
@@ -500,7 +513,7 @@ impl Context {
             .or_else(|| self.future_defined_locals.get(&ident.inspect()[..]))
         {
             match self.validate_visibility(ident, vi, input, namespace) {
-                Ok(()) => {
+                Ok(()) if acc_kind.matches(vi) => {
                     return Triple::Ok(vi.clone());
                 }
                 Err(err) => {
@@ -508,6 +521,7 @@ impl Context {
                         return Triple::Err(err);
                     }
                 }
+                _ => {}
             }
         }
         if acc_kind.is_local() {
@@ -562,9 +576,10 @@ impl Context {
             }
             _ => {}
         }
+        // class/module attr
         if let Ok(singular_ctxs) = self.get_singular_ctxs_by_hir_expr(obj, namespace) {
             for ctx in singular_ctxs {
-                match ctx.rec_get_var_info(ident, AccessKind::Attr, input, namespace) {
+                match ctx.rec_get_var_info(ident, AccessKind::UnboundAttr, input, namespace) {
                     Triple::Ok(vi) => {
                         return Triple::Ok(vi);
                     }
@@ -575,7 +590,8 @@ impl Context {
                 }
             }
         }
-        match self.get_attr_from_nominal_t(obj, ident, input, namespace) {
+        // bound method/instance attr
+        match self.get_bound_attr_from_nominal_t(obj, ident, input, namespace) {
             Triple::Ok(vi) => {
                 if let Some(self_t) = vi.t.self_t() {
                     match self
@@ -636,7 +652,7 @@ impl Context {
         Triple::None
     }
 
-    fn get_attr_from_nominal_t(
+    fn get_bound_attr_from_nominal_t(
         &self,
         obj: &hir::Expr,
         ident: &Identifier,
@@ -646,7 +662,7 @@ impl Context {
         let self_t = obj.t();
         if let Some(sups) = self.get_nominal_super_type_ctxs(&self_t) {
             for ctx in sups {
-                match ctx.rec_get_var_info(ident, AccessKind::Attr, input, namespace) {
+                match ctx.rec_get_var_info(ident, AccessKind::BoundAttr, input, namespace) {
                     Triple::Ok(vi) => {
                         return Triple::Ok(vi);
                     }
@@ -657,7 +673,7 @@ impl Context {
                 }
                 // if self is a methods context
                 if let Some(ctx) = self.get_same_name_context(&ctx.name) {
-                    match ctx.rec_get_var_info(ident, AccessKind::Method, input, namespace) {
+                    match ctx.rec_get_var_info(ident, AccessKind::BoundAttr, input, namespace) {
                         Triple::Ok(vi) => {
                             return Triple::Ok(vi);
                         }
@@ -691,7 +707,7 @@ impl Context {
                 }
             };
             for ctx in ctxs {
-                match ctx.rec_get_var_info(ident, AccessKind::Attr, input, namespace) {
+                match ctx.rec_get_var_info(ident, AccessKind::BoundAttr, input, namespace) {
                     Triple::Ok(vi) => {
                         obj.ref_t().coerce();
                         return Triple::Ok(vi);
@@ -702,7 +718,7 @@ impl Context {
                     _ => {}
                 }
                 if let Some(ctx) = self.get_same_name_context(&ctx.name) {
-                    match ctx.rec_get_var_info(ident, AccessKind::Method, input, namespace) {
+                    match ctx.rec_get_var_info(ident, AccessKind::BoundAttr, input, namespace) {
                         Triple::Ok(vi) => {
                             return Triple::Ok(vi);
                         }
@@ -946,7 +962,7 @@ impl Context {
                 }
             }
             if let Some(ctx) = self.get_same_name_context(&ctx.name) {
-                match ctx.rec_get_var_info(attr_name, AccessKind::Method, input, namespace) {
+                match ctx.rec_get_var_info(attr_name, AccessKind::BoundAttr, input, namespace) {
                     Triple::Ok(t) => {
                         return Ok(t);
                     }
@@ -3072,4 +3088,58 @@ impl Context {
             )))
         }
     }
+
+    pub(crate) fn get_instance_attr(&self, name: &str) -> Option<&VarInfo> {
+        if let Some(vi) = self.locals.get(name) {
+            if vi.kind.is_instance_attr() {
+                return Some(vi);
+            }
+        }
+        if let Some(vi) = self.decls.get(name) {
+            if vi.kind.is_instance_attr() {
+                return Some(vi);
+            }
+        }
+        if self.kind.is_method_def() {
+            self.get_nominal_type_ctx(&mono(&self.name))
+                .and_then(|(_, ctx)| ctx.get_instance_attr(name))
+        } else {
+            self.methods_list.iter().find_map(|(_, ctx)| {
+                if ctx.kind.is_trait_impl() {
+                    None
+                } else {
+                    ctx.get_instance_attr(name)
+                }
+            })
+        }
+    }
+
+    /// does not remove instance attribute declarations
+    pub(crate) fn remove_class_attr(&mut self, name: &str) -> Option<(VarName, VarInfo)> {
+        if let Some((k, v)) = self.locals.remove_entry(name) {
+            if v.kind.is_instance_attr() {
+                self.locals.insert(k, v);
+            } else {
+                return Some((k, v));
+            }
+        } else if let Some((k, v)) = self.decls.remove_entry(name) {
+            if v.kind.is_instance_attr() {
+                self.decls.insert(k, v);
+            } else {
+                return Some((k, v));
+            }
+        }
+        if self.kind.is_method_def() {
+            self.get_mut_nominal_type_ctx(&mono(&self.name))
+                .and_then(|(_, ctx)| ctx.remove_class_attr(name))
+        } else {
+            self.methods_list.iter_mut().find_map(|(_, ctx)| {
+                if ctx.kind.is_trait_impl() {
+                    None
+                } else {
+                    ctx.remove_class_attr(name)
+                }
+            })
+        }
+    }
 }

crates/erg_compiler/context/mod.rs

@@ -319,6 +319,10 @@ impl ContextKind {
         matches!(self, Self::MethodDefs(_))
     }
 
+    pub const fn is_trait_impl(&self) -> bool {
+        matches!(self, Self::MethodDefs(Some(_)))
+    }
+
     pub const fn is_type(&self) -> bool {
         matches!(self, Self::Class | Self::Trait | Self::StructuralTrait)
     }

crates/erg_compiler/context/register.rs

@@ -9,6 +9,7 @@ use std::time::{Duration, SystemTime};
 
 use erg_common::config::ErgMode;
 use erg_common::consts::{ERG_MODE, PYTHON_MODE};
+use erg_common::dict::Dict;
 use erg_common::env::{is_pystd_main_module, is_std_decl_path};
 use erg_common::erg_util::BUILTIN_ERG_MODS;
 use erg_common::levenshtein::get_similar_name;
@@ -32,7 +33,7 @@ use crate::ty::free::{Constraint, HasLevel};
 use crate::ty::typaram::TyParam;
 use crate::ty::value::{GenTypeObj, TypeObj, ValueObj};
 use crate::ty::{
-    GuardType, HasType, ParamTy, SubrType, Type, Variable, Visibility, VisibilityModifier,
+    Field, GuardType, HasType, ParamTy, SubrType, Type, Variable, Visibility, VisibilityModifier,
 };
 
 use crate::build_hir::HIRBuilder;
@@ -200,7 +201,10 @@ impl Context {
         } else {
             None
         };
-        if let Some(_decl) = self.decls.remove(&ident.name) {
+        if self
+            .remove_class_attr(ident.name.inspect())
+            .is_some_and(|(_, decl)| !decl.kind.is_auto())
+        {
             Err(TyCheckErrors::from(TyCheckError::duplicate_decl_error(
                 self.cfg.input.clone(),
                 line!() as usize,
@@ -266,7 +270,10 @@ impl Context {
             self.absolutize(sig.ident.name.loc()),
         );
         self.index().register(&vi);
-        if let Some(_decl) = self.decls.remove(name) {
+        if self
+            .remove_class_attr(name)
+            .is_some_and(|(_, decl)| !decl.kind.is_auto())
+        {
             Err(TyCheckErrors::from(TyCheckError::duplicate_decl_error(
                 self.cfg.input.clone(),
                 line!() as usize,
@@ -1347,16 +1354,7 @@ impl Context {
                                 ..
                             } = additional
                             {
-                                for (field, t) in rec.iter() {
-                                    let varname = VarName::from_str(field.symbol.clone());
-                                    let vi = VarInfo::instance_attr(
-                                        field.clone(),
-                                        t.clone(),
-                                        self.impl_of(),
-                                        ctx.name.clone(),
-                                    );
-                                    ctx.decls.insert(varname, vi);
-                                }
+                                self.register_instance_attrs(&mut ctx, rec)?;
                             }
                             param_t
                                 .map(|t| self.intersection(t, additional.typ()))
@@ -1418,16 +1416,7 @@ impl Context {
                         self.level,
                     );
                     let Some(TypeObj::Builtin{ t: Type::Record(req), .. }) = gen.base_or_sup() else { todo!("{gen}") };
-                    for (field, t) in req.iter() {
-                        let vi = VarInfo::instance_attr(
-                            field.clone(),
-                            t.clone(),
-                            self.impl_of(),
-                            ctx.name.clone(),
-                        );
-                        ctx.decls
-                            .insert(VarName::from_str(field.symbol.clone()), vi);
-                    }
+                    self.register_instance_attrs(&mut ctx, req)?;
                     self.register_gen_mono_type(ident, gen, ctx, Const)
                 } else {
                     feature_error!(
@@ -1460,16 +1449,7 @@ impl Context {
                         None
                     };
                     if let Some(additional) = additional {
-                        for (field, t) in additional.iter() {
-                            let vi = VarInfo::instance_attr(
-                                field.clone(),
-                                t.clone(),
-                                self.impl_of(),
-                                ctx.name.clone(),
-                            );
-                            ctx.decls
-                                .insert(VarName::from_str(field.symbol.clone()), vi);
-                        }
+                        self.register_instance_attrs(&mut ctx, additional)?;
                     }
                     for sup in super_classes.into_iter() {
                         if let Some((_, sup_ctx)) = self.get_nominal_type_ctx(&sup) {
@@ -1521,6 +1501,29 @@ impl Context {
         }
     }
 
+    fn register_instance_attrs(
+        &self,
+        ctx: &mut Context,
+        rec: &Dict<Field, Type>,
+    ) -> CompileResult<()> {
+        for (field, t) in rec.iter() {
+            let varname = VarName::from_str(field.symbol.clone());
+            let vi =
+                VarInfo::instance_attr(field.clone(), t.clone(), self.impl_of(), ctx.name.clone());
+            // self.index().register(&vi);
+            if let Some(_ent) = ctx.decls.insert(varname.clone(), vi) {
+                return Err(CompileErrors::from(CompileError::duplicate_decl_error(
+                    self.cfg.input.clone(),
+                    line!() as usize,
+                    varname.loc(),
+                    self.caused_by(),
+                    varname.inspect(),
+                )));
+            }
+        }
+        Ok(())
+    }
+
     fn gen_class_new_method(&self, gen: &GenTypeObj, ctx: &mut Context) -> CompileResult<()> {
         let mut methods = Self::methods(None, self.cfg.clone(), self.shared.clone(), 2, self.level);
         let new_t = if let Some(base) = gen.base_or_sup() {
@@ -1529,16 +1532,7 @@ impl Context {
                     t: Type::Record(rec),
                     ..
                 } => {
-                    for (field, t) in rec.iter() {
-                        let varname = VarName::from_str(field.symbol.clone());
-                        let vi = VarInfo::instance_attr(
-                            field.clone(),
-                            t.clone(),
-                            self.impl_of(),
-                            ctx.name.clone(),
-                        );
-                        ctx.decls.insert(varname, vi);
-                    }
+                    self.register_instance_attrs(ctx, rec)?;
                 }
                 other => {
                     methods.register_fixed_auto_impl(

crates/erg_compiler/declare.rs

@@ -177,7 +177,7 @@ impl ASTLowerer {
                     for ctx in ctxs {
                         if let Triple::Ok(vi) = ctx.rec_get_var_info(
                             &ident.raw,
-                            AccessKind::Attr,
+                            AccessKind::UnboundAttr,
                             self.input(),
                             &self.module.context,
                         ) {

crates/erg_compiler/error/lower.rs

@@ -485,11 +485,12 @@ impl LowerError {
     ) -> Self {
         let hint = similar_name.map(|n| {
             let vis = similar_info.map_or("".into(), |vi| vi.vis.modifier.display());
+            let kind = similar_info.map_or("", |vi| vi.kind.display());
             switch_lang!(
-                "japanese" => format!("似た名前の{vis}属性があります: {n}"),
-                "simplified_chinese" => format!("具有相同名称的{vis}属性: {n}"),
-                "traditional_chinese" => format!("具有相同名稱的{vis}屬性: {n}"),
-                "english" => format!("has a similar name {vis} attribute: {n}"),
+                "japanese" => format!("似た名前の{vis}{kind}属性があります: {n}"),
+                "simplified_chinese" => format!("具有相同名称的{vis}{kind}属性: {n}"),
+                "traditional_chinese" => format!("具有相同名稱的{vis}{kind}屬性: {n}"),
+                "english" => format!("has a similar name {vis} {kind} attribute: {n}"),
             )
         });
         let found = StyledString::new(name, Some(ERR), Some(ATTR));
@@ -1157,4 +1158,30 @@ impl LowerWarning {
             caused_by,
         )
     }
+
+    pub fn same_name_instance_attr_warning(
+        input: Input,
+        errno: usize,
+        loc: Location,
+        caused_by: String,
+        name: &str,
+    ) -> Self {
+        let name = StyledStr::new(readable_name(name), Some(WARN), Some(ATTR));
+        Self::new(
+            ErrorCore::new(
+                vec![SubMessage::only_loc(loc)],
+                switch_lang!(
+                    "japanese" => format!("同名のインスタンス属性{name}が存在します"),
+                    "simplified_chinese" => format!("同名的实例属性{name}已存在"),
+                    "traditional_chinese" => format!("同名的實例屬性{name}已存在"),
+                    "english" => format!("an instance attribute named {name} already exists"),
+                ),
+                errno,
+                NameWarning,
+                loc,
+            ),
+            input,
+            caused_by,
+        )
+    }
 }

crates/erg_compiler/varinfo.rs

@@ -3,7 +3,7 @@ use std::path::PathBuf;
 
 use erg_common::error::Location;
 use erg_common::set::Set;
-use erg_common::Str;
+use erg_common::{switch_lang, Str};
 
 use erg_parser::ast::DefId;
 
@@ -39,6 +39,7 @@ use Mutability::*;
 pub enum VarKind {
     Defined(DefId),
     Declared,
+    InstanceAttr,
     Parameter {
         def_id: DefId,
         var: bool,
@@ -88,6 +89,38 @@ impl VarKind {
     pub const fn is_builtin(&self) -> bool {
         matches!(self, Self::Builtin)
     }
+
+    pub const fn is_auto(&self) -> bool {
+        matches!(self, Self::Auto)
+    }
+
+    pub const fn is_instance_attr(&self) -> bool {
+        matches!(self, Self::InstanceAttr)
+    }
+
+    pub const fn display(&self) -> &'static str {
+        match self {
+            Self::Auto | Self::FixedAuto => switch_lang!(
+                "japanese" => "自動",
+                "simplified_chinese" => "自动",
+                "traditional_chinese" => "自動",
+                "english" => "auto",
+            ),
+            Self::Builtin => switch_lang!(
+                "japanese" => "組み込み",
+                "simplified_chinese" => "内置",
+                "traditional_chinese" => "內置",
+                "english" => "builtin",
+            ),
+            Self::InstanceAttr => switch_lang!(
+                "japanese" => "インスタンス",
+                "simplified_chinese" => "实例",
+                "traditional_chinese" => "實例",
+                "english" => "instance",
+            ),
+            _ => "",
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -285,12 +318,11 @@ impl VarInfo {
         } else {
             Mutability::Immutable
         };
-        let kind = VarKind::Declared;
         Self::new(
             t,
             muty,
             Visibility::new(field.vis, namespace),
-            kind,
+            VarKind::InstanceAttr,
             None,
             impl_of,
             None,

tests/should_err/class_attr.er

@@ -0,0 +1,9 @@
+C = Class { .x = Int; .y = Int }
+C.
+    x = "aa"
+
+_: Str = C.x
+_ = C.y # ERR
+c = C.new({.x = 1; .y = 2})
+_: Int = c.x
+_: Int = c.y

tests/test.rs

@@ -273,6 +273,11 @@ fn exec_assert_cast() -> Result<(), ()> {
     expect_failure("examples/assert_cast.er", 0, 3)
 }
 
+#[test]
+fn exec_class_attr_err() -> Result<(), ()> {
+    expect_failure("tests/should_err/class_attr.er", 1, 1)
+}
+
 #[test]
 fn exec_collection_err() -> Result<(), ()> {
     expect_failure("tests/should_err/collection.er", 0, 4)