vhdl-sem_names: allow element attribute on element attribute. Fix #2141

4 files changed, 34 insertions, 17 deletions

diff --git a/src/vhdl/translate/trans-chap4.adb b/src/vhdl/translate/trans-chap4.adb
index 699f4acc9..a536fb07c 100644
--- a/src/vhdl/translate/trans-chap4.adb
+++ b/src/vhdl/translate/trans-chap4.adb
@@ -453,25 +453,36 @@ package body Trans.Chap4 is
                           Iir_Kind_Element_Attribute);
    end Is_Object_Type_Attribute;
 
-   procedure Elab_Subtype_Attribute
-     (Decl : Iir; Name_Val : Mnode; Name_Sig : Mnode)
+   --  Handle 'Subtype or 'Element, return the bounds.
+   function Type_Attribute_To_Bounds (Attr : Iir) return Mnode
    is
-      Ind : constant Iir := Get_Subtype_Indication (Decl);
+      Pfx : constant Iir := Get_Prefix (Attr);
       Name : Mnode;
       Bnd : Mnode;
    begin
-      Name := Chap6.Translate_Name (Get_Prefix (Ind), Mode_Value);
-      Bnd := Chap3.Get_Composite_Bounds (Name);
-      case Get_Kind (Ind) is
+      if Get_Kind (Pfx) = Iir_Kind_Element_Attribute then
+         Bnd := Type_Attribute_To_Bounds (Pfx);
+      else
+         Name := Chap6.Translate_Name (Pfx, Mode_Value);
+         Bnd := Chap3.Get_Composite_Bounds (Name);
+      end if;
+
+      case Get_Kind (Attr) is
          when Iir_Kind_Subtype_Attribute =>
-            null;
+            return Bnd;
          when Iir_Kind_Element_Attribute =>
-            Bnd := Chap3.Array_Bounds_To_Element_Bounds
-              (Bnd, Get_Type (Get_Prefix (Ind)));
+            return Chap3.Array_Bounds_To_Element_Bounds (Bnd, Get_Type (Pfx));
          when others =>
             raise Internal_Error;
       end case;
+   end Type_Attribute_To_Bounds;
 
+   procedure Elab_Subtype_Attribute
+     (Decl : Iir; Name_Val : Mnode; Name_Sig : Mnode)
+   is
+      Bnd : Mnode;
+   begin
+      Bnd := Type_Attribute_To_Bounds (Get_Subtype_Indication (Decl));
       if Name_Sig /= Mnode_Null then
          Stabilize (Bnd);
          New_Assign_Stmt (M2Lp (Chap3.Get_Composite_Bounds (Name_Sig)),
diff --git a/src/vhdl/translate/trans-chap8.adb b/src/vhdl/translate/trans-chap8.adb
index 05cac2c56..56f985adc 100644
--- a/src/vhdl/translate/trans-chap8.adb
+++ b/src/vhdl/translate/trans-chap8.adb
@@ -473,6 +473,8 @@ package body Trans.Chap8 is
                   null;
                when Iir_Kind_Subtype_Declaration =>
                   null;
+               when Iir_Kind_Element_Attribute =>
+                  null;
                when others =>
                   Error_Kind ("is_for_loop_iterator_stable(2)", Name);
             end case;
diff --git a/src/vhdl/vhdl-sem_names.adb b/src/vhdl/vhdl-sem_names.adb
index 3993cae22..1847b6205 100644
--- a/src/vhdl/vhdl-sem_names.adb
+++ b/src/vhdl/vhdl-sem_names.adb
@@ -3858,23 +3858,25 @@ package body Vhdl.Sem_Names is
           in Iir_Kinds_Object_Declaration)
       then
          Attr_Type := Get_Type (Prefix_Name);
-      elsif (Get_Kind (Get_Base_Name (Prefix_Name))
-          in Iir_Kinds_Type_Declaration)
-      then
-         Attr_Type := Get_Type (Get_Base_Name (Prefix_Name));
+         Attr_Subtype := Get_Element_Subtype (Attr_Type);
       else
-         Error_Msg_Sem (+Attr, "prefix must denote an object or a type");
+         Attr_Type := Is_Type_Name (Prefix_Name);
+         if Attr_Type /= Null_Iir then
+            Attr_Subtype := Get_Element_Subtype (Attr_Type);
+         else
+            Error_Msg_Sem (+Attr, "prefix must denote an object or a type");
+            Attr_Subtype := Create_Error_Type (Attr);
+         end if;
       end if;
 
-      if False and not Is_Array_Type (Attr_Type) then
+      if False and then not Is_Array_Type (Attr_Type) then
          Error_Msg_Sem (+Attr, "prefix must denote an array");
       end if;
 
       --  The type defined by 'element is always constrained.  Create
       --  a subtype if it is not.
       --  NO, it isn't.  The prefix can be a type.
-      Attr_Subtype := Get_Element_Subtype (Attr_Type);
-      if False and not Is_Fully_Constrained_Type (Attr_Subtype) then
+      if False and then not Is_Fully_Constrained_Type (Attr_Subtype) then
          Attr_Subtype :=
              Sem_Types.Build_Constrained_Subtype (Attr_Subtype, Attr);
       end if;
diff --git a/src/vhdl/vhdl-utils.adb b/src/vhdl/vhdl-utils.adb
index 800a0c9df..729e7352b 100644
--- a/src/vhdl/vhdl-utils.adb
+++ b/src/vhdl/vhdl-utils.adb
@@ -1213,6 +1213,8 @@ package body Vhdl.Utils is
             end case;
          when Iir_Kind_Subtype_Attribute =>
             return Get_Type (Ent);
+         when Iir_Kind_Element_Attribute =>
+            return Get_Type (Name);
          when others =>
             return Null_Iir;
       end case;