Preliminary work to support external names (parse, semantic)

12 files changed, 659 insertions, 112 deletions

diff --git a/src/vhdl/errorout.adb b/src/vhdl/errorout.adb
index 7928b7485..442aeb047 100644
--- a/src/vhdl/errorout.adb
+++ b/src/vhdl/errorout.adb
@@ -479,6 +479,22 @@ package body Errorout is
             return '''
               & Name_Table.Nam_Buffer (1 .. Name_Table.Nam_Length)
               & ''';
+         when Iir_Kind_External_Constant_Name =>
+            return "external constant name";
+         when Iir_Kind_External_Signal_Name =>
+            return "external signal name";
+         when Iir_Kind_External_Variable_Name =>
+            return "external variable name";
+
+         when Iir_Kind_Package_Pathname =>
+            return "package pathname";
+         when Iir_Kind_Absolute_Pathname =>
+            return "absolute pathname";
+         when Iir_Kind_Relative_Pathname =>
+            return "relative pathname";
+         when Iir_Kind_Pathname_Element =>
+            return "pathname element";
+
          when Iir_Kind_Entity_Aspect_Entity =>
             return "aspect " & Disp_Node (Get_Entity (Node))
               & '(' & Image_Identifier (Get_Architecture (Node)) & ')';
diff --git a/src/vhdl/iirs.adb b/src/vhdl/iirs.adb
index cb174cea5..609d9fd21 100644
--- a/src/vhdl/iirs.adb
+++ b/src/vhdl/iirs.adb
@@ -406,6 +406,13 @@ package body Iirs is
            | Iir_Kind_Operator_Symbol
            | Iir_Kind_Selected_By_All_Name
            | Iir_Kind_Parenthesis_Name
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name
+           | Iir_Kind_Package_Pathname
+           | Iir_Kind_Absolute_Pathname
+           | Iir_Kind_Relative_Pathname
+           | Iir_Kind_Pathname_Element
            | Iir_Kind_Base_Attribute
            | Iir_Kind_Left_Type_Attribute
            | Iir_Kind_Right_Type_Attribute
@@ -4195,6 +4202,54 @@ package body Iirs is
       Set_Field1 (Sign, Prefix);
    end Set_Signature_Prefix;
 
+   function Get_External_Pathname (Name : Iir) return Iir is
+   begin
+      pragma Assert (Name /= Null_Iir);
+      pragma Assert (Has_External_Pathname (Get_Kind (Name)),
+                     "no field External_Pathname");
+      return Get_Field3 (Name);
+   end Get_External_Pathname;
+
+   procedure Set_External_Pathname (Name : Iir; Path : Iir) is
+   begin
+      pragma Assert (Name /= Null_Iir);
+      pragma Assert (Has_External_Pathname (Get_Kind (Name)),
+                     "no field External_Pathname");
+      Set_Field3 (Name, Path);
+   end Set_External_Pathname;
+
+   function Get_Pathname_Suffix (Path : Iir) return Iir is
+   begin
+      pragma Assert (Path /= Null_Iir);
+      pragma Assert (Has_Pathname_Suffix (Get_Kind (Path)),
+                     "no field Pathname_Suffix");
+      return Get_Field2 (Path);
+   end Get_Pathname_Suffix;
+
+   procedure Set_Pathname_Suffix (Path : Iir; Suffix : Iir) is
+   begin
+      pragma Assert (Path /= Null_Iir);
+      pragma Assert (Has_Pathname_Suffix (Get_Kind (Path)),
+                     "no field Pathname_Suffix");
+      Set_Field2 (Path, Suffix);
+   end Set_Pathname_Suffix;
+
+   function Get_Pathname_Expression (Path : Iir) return Iir is
+   begin
+      pragma Assert (Path /= Null_Iir);
+      pragma Assert (Has_Pathname_Expression (Get_Kind (Path)),
+                     "no field Pathname_Expression");
+      return Get_Field5 (Path);
+   end Get_Pathname_Expression;
+
+   procedure Set_Pathname_Expression (Path : Iir; Expr : Iir) is
+   begin
+      pragma Assert (Path /= Null_Iir);
+      pragma Assert (Has_Pathname_Expression (Get_Kind (Path)),
+                     "no field Pathname_Expression");
+      Set_Field5 (Path, Expr);
+   end Set_Pathname_Expression;
+
    function Get_Slice_Subtype (Slice : Iir) return Iir is
    begin
       pragma Assert (Slice /= Null_Iir);
diff --git a/src/vhdl/iirs.ads b/src/vhdl/iirs.ads
index 922ab472b..e8a1b74ec 100644
--- a/src/vhdl/iirs.ads
+++ b/src/vhdl/iirs.ads
@@ -3253,6 +3253,59 @@ package Iirs is
    --
    --   Get/Set_Name_Staticness (State2)
 
+   -- Iir_Kind_External_Constant_Name (Short)
+   -- Iir_Kind_External_Signal_Name (Short)
+   -- Iir_Kind_External_Variable_Name (Short)
+   --
+   --   Get/Set_Parent (Field0)
+   --
+   --   Get/Set_Type (Field1)
+   --
+   --   Get/Set_Chain (Field2)
+   --
+   --   Get/Set_External_Pathname (Field3)
+   --
+   --   Get/Set_Subtype_Indication (Field5)
+   --
+   --  Only for Iir_Kind_External_Variable_Name:
+   --   Get/Set_Shared_Flag (Flag2)
+   --
+   --   Get/Set_Is_Ref (Flag7)
+   --
+   --   Get/Set_Expr_Staticness (State1)
+   --
+   --   Get/Set_Name_Staticness (State2)
+
+   -- Iir_Kind_Package_Pathname (Short)
+   --  This node represents only the library_logical_name. Package and object
+   --  simple_names are represented by Selected_Name.
+   --
+   --   Get/Set_Pathname_Suffix (Field2)
+   --
+   --   Get/Set_Identifier (Field3)
+   --
+   --   Get/Set_Named_Entity (Field4)
+
+   -- Iir_Kind_Absolute_Pathname (Short)
+   --  Represents only the '.'.
+   --
+   --   Get/Set_Pathname_Suffix (Field2)
+
+   -- Iir_Kind_Relative_Pathname (Short)
+   --  Represents only one '^.'
+   --
+   --   Get/Set_Pathname_Suffix (Field2)
+
+   -- Iir_Kind_Pathname_Element (Short)
+   --
+   --   Get/Set_Pathname_Suffix (Field2)
+   --
+   --   Get/Set_Identifier (Field3)
+   --
+   --   Get/Set_Named_Entity (Field4)
+   --
+   --   Get/Set_Pathname_Expression (Field5)
+
    -----------------
    --  Attributes --
    -----------------
@@ -3678,6 +3731,15 @@ package Iirs is
       Iir_Kind_Selected_By_All_Name,
       Iir_Kind_Parenthesis_Name,
 
+      Iir_Kind_External_Constant_Name,
+      Iir_Kind_External_Signal_Name,
+      Iir_Kind_External_Variable_Name,
+
+      Iir_Kind_Package_Pathname,
+      Iir_Kind_Absolute_Pathname,
+      Iir_Kind_Relative_Pathname,
+      Iir_Kind_Pathname_Element,
+
    -- Attributes
       Iir_Kind_Base_Attribute,
       Iir_Kind_Left_Type_Attribute,            --  type_attribute
@@ -4415,6 +4477,11 @@ package Iirs is
      Iir_Kind_Dereference ..
      Iir_Kind_Implicit_Dereference;
 
+   subtype Iir_Kinds_External_Name is Iir_Kind range
+     Iir_Kind_External_Constant_Name ..
+   --Iir_Kind_External_Signal_Name
+     Iir_Kind_External_Variable_Name;
+
    --  Any attribute that is an expression.
    subtype Iir_Kinds_Expression_Attribute is Iir_Kind range
      Iir_Kind_Left_Type_Attribute ..
@@ -4552,50 +4619,6 @@ package Iirs is
    --Iir_Kind_Disconnection_Specification
      Iir_Kind_Configuration_Specification;
 
-   subtype Iir_Kinds_Declaration is Iir_Kind range
-     Iir_Kind_Type_Declaration ..
-   --Iir_Kind_Anonymous_Type_Declaration
-   --Iir_Kind_Subtype_Declaration
-   --Iir_Kind_Nature_Declaration
-   --Iir_Kind_Subnature_Declaration
-   --Iir_Kind_Package_Declaration
-   --Iir_Kind_Package_Instantiation_Declaration
-   --Iir_Kind_Package_Body
-   --Iir_Kind_Configuration_Declaration
-   --Iir_Kind_Entity_Declaration
-   --Iir_Kind_Architecture_Body
-   --Iir_Kind_Context_Declaration
-   --Iir_Kind_Package_Header
-   --Iir_Kind_Unit_Declaration
-   --Iir_Kind_Library_Declaration
-   --Iir_Kind_Component_Declaration
-   --Iir_Kind_Attribute_Declaration
-   --Iir_Kind_Group_Template_Declaration
-   --Iir_Kind_Group_Declaration
-   --Iir_Kind_Element_Declaration
-   --Iir_Kind_Non_Object_Alias_Declaration
-   --Iir_Kind_Psl_Declaration
-   --Iir_Kind_Terminal_Declaration
-   --Iir_Kind_Free_Quantity_Declaration
-   --Iir_Kind_Across_Quantity_Declaration
-   --Iir_Kind_Through_Quantity_Declaration
-   --Iir_Kind_Enumeration_Literal
-   --Iir_Kind_Function_Declaration
-   --Iir_Kind_Procedure_Declaration
-   --Iir_Kind_Function_Body
-   --Iir_Kind_Procedure_Body
-   --Iir_Kind_Object_Alias_Declaration
-   --Iir_Kind_File_Declaration
-   --Iir_Kind_Guard_Signal_Declaration
-   --Iir_Kind_Signal_Declaration
-   --Iir_Kind_Variable_Declaration
-   --Iir_Kind_Constant_Declaration
-   --Iir_Kind_Iterator_Declaration
-   --Iir_Kind_Interface_Constant_Declaration
-   --Iir_Kind_Interface_Variable_Declaration
-   --Iir_Kind_Interface_Signal_Declaration
-     Iir_Kind_Interface_File_Declaration;
-
    -------------------------------------
    -- Types and subtypes declarations --
    -------------------------------------
@@ -6173,6 +6196,19 @@ package Iirs is
    function Get_Signature_Prefix (Sign : Iir) return Iir;
    procedure Set_Signature_Prefix (Sign : Iir; Prefix : Iir);
 
+   --  External pathname for an external name.
+   --  Field: Field3
+   function Get_External_Pathname (Name : Iir) return Iir;
+   procedure Set_External_Pathname (Name : Iir; Path : Iir);
+
+   --  Field: Field2
+   function Get_Pathname_Suffix (Path : Iir) return Iir;
+   procedure Set_Pathname_Suffix (Path : Iir; Suffix : Iir);
+
+   --  Field: Field5
+   function Get_Pathname_Expression (Path : Iir) return Iir;
+   procedure Set_Pathname_Expression (Path : Iir; Expr : Iir);
+
    --  The subtype of a slice.  Contrary to the Type field, this is not a
    --  reference.
    --  Field: Field3
diff --git a/src/vhdl/nodes_meta.adb b/src/vhdl/nodes_meta.adb
index 8e380ae40..cbe86fbc3 100644
--- a/src/vhdl/nodes_meta.adb
+++ b/src/vhdl/nodes_meta.adb
@@ -249,6 +249,9 @@ package body Nodes_Meta is
       Field_Name_Staticness => Type_Iir_Staticness,
       Field_Prefix => Type_Iir,
       Field_Signature_Prefix => Type_Iir,
+      Field_External_Pathname => Type_Iir,
+      Field_Pathname_Suffix => Type_Iir,
+      Field_Pathname_Expression => Type_Iir,
       Field_Slice_Subtype => Type_Iir,
       Field_Suffix => Type_Iir,
       Field_Index_Subtype => Type_Iir,
@@ -782,6 +785,12 @@ package body Nodes_Meta is
             return "prefix";
          when Field_Signature_Prefix =>
             return "signature_prefix";
+         when Field_External_Pathname =>
+            return "external_pathname";
+         when Field_Pathname_Suffix =>
+            return "pathname_suffix";
+         when Field_Pathname_Expression =>
+            return "pathname_expression";
          when Field_Slice_Subtype =>
             return "slice_subtype";
          when Field_Suffix =>
@@ -1320,6 +1329,20 @@ package body Nodes_Meta is
             return "selected_by_all_name";
          when Iir_Kind_Parenthesis_Name =>
             return "parenthesis_name";
+         when Iir_Kind_External_Constant_Name =>
+            return "external_constant_name";
+         when Iir_Kind_External_Signal_Name =>
+            return "external_signal_name";
+         when Iir_Kind_External_Variable_Name =>
+            return "external_variable_name";
+         when Iir_Kind_Package_Pathname =>
+            return "package_pathname";
+         when Iir_Kind_Absolute_Pathname =>
+            return "absolute_pathname";
+         when Iir_Kind_Relative_Pathname =>
+            return "relative_pathname";
+         when Iir_Kind_Pathname_Element =>
+            return "pathname_element";
          when Iir_Kind_Base_Attribute =>
             return "base_attribute";
          when Iir_Kind_Left_Type_Attribute =>
@@ -1864,6 +1887,12 @@ package body Nodes_Meta is
             return Attr_None;
          when Field_Signature_Prefix =>
             return Attr_Ref;
+         when Field_External_Pathname =>
+            return Attr_None;
+         when Field_Pathname_Suffix =>
+            return Attr_None;
+         when Field_Pathname_Expression =>
+            return Attr_None;
          when Field_Slice_Subtype =>
             return Attr_None;
          when Field_Suffix =>
@@ -3620,6 +3649,50 @@ package body Nodes_Meta is
       Field_Association_Chain,
       Field_Type,
       Field_Named_Entity,
+      --  Iir_Kind_External_Constant_Name
+      Field_Shared_Flag,
+      Field_Is_Ref,
+      Field_Expr_Staticness,
+      Field_Name_Staticness,
+      Field_Chain,
+      Field_External_Pathname,
+      Field_Subtype_Indication,
+      Field_Parent,
+      Field_Type,
+      --  Iir_Kind_External_Signal_Name
+      Field_Shared_Flag,
+      Field_Is_Ref,
+      Field_Expr_Staticness,
+      Field_Name_Staticness,
+      Field_Chain,
+      Field_External_Pathname,
+      Field_Subtype_Indication,
+      Field_Parent,
+      Field_Type,
+      --  Iir_Kind_External_Variable_Name
+      Field_Shared_Flag,
+      Field_Is_Ref,
+      Field_Expr_Staticness,
+      Field_Name_Staticness,
+      Field_Chain,
+      Field_External_Pathname,
+      Field_Subtype_Indication,
+      Field_Parent,
+      Field_Type,
+      --  Iir_Kind_Package_Pathname
+      Field_Identifier,
+      Field_Pathname_Suffix,
+      Field_Named_Entity,
+      Field_Base_Name,
+      --  Iir_Kind_Absolute_Pathname
+      Field_Pathname_Suffix,
+      --  Iir_Kind_Relative_Pathname
+      Field_Pathname_Suffix,
+      --  Iir_Kind_Pathname_Element
+      Field_Identifier,
+      Field_Pathname_Suffix,
+      Field_Pathname_Expression,
+      Field_Named_Entity,
       --  Iir_Kind_Base_Attribute
       Field_Prefix,
       Field_Type,
@@ -4082,45 +4155,52 @@ package body Nodes_Meta is
       Iir_Kind_Operator_Symbol => 1412,
       Iir_Kind_Selected_By_All_Name => 1417,
       Iir_Kind_Parenthesis_Name => 1421,
-      Iir_Kind_Base_Attribute => 1423,
-      Iir_Kind_Left_Type_Attribute => 1428,
-      Iir_Kind_Right_Type_Attribute => 1433,
-      Iir_Kind_High_Type_Attribute => 1438,
-      Iir_Kind_Low_Type_Attribute => 1443,
-      Iir_Kind_Ascending_Type_Attribute => 1448,
-      Iir_Kind_Image_Attribute => 1454,
-      Iir_Kind_Value_Attribute => 1460,
-      Iir_Kind_Pos_Attribute => 1466,
-      Iir_Kind_Val_Attribute => 1472,
-      Iir_Kind_Succ_Attribute => 1478,
-      Iir_Kind_Pred_Attribute => 1484,
-      Iir_Kind_Leftof_Attribute => 1490,
-      Iir_Kind_Rightof_Attribute => 1496,
-      Iir_Kind_Delayed_Attribute => 1504,
-      Iir_Kind_Stable_Attribute => 1512,
-      Iir_Kind_Quiet_Attribute => 1520,
-      Iir_Kind_Transaction_Attribute => 1528,
-      Iir_Kind_Event_Attribute => 1532,
-      Iir_Kind_Active_Attribute => 1536,
-      Iir_Kind_Last_Event_Attribute => 1540,
-      Iir_Kind_Last_Active_Attribute => 1544,
-      Iir_Kind_Last_Value_Attribute => 1548,
-      Iir_Kind_Driving_Attribute => 1552,
-      Iir_Kind_Driving_Value_Attribute => 1556,
-      Iir_Kind_Behavior_Attribute => 1556,
-      Iir_Kind_Structure_Attribute => 1556,
-      Iir_Kind_Simple_Name_Attribute => 1563,
-      Iir_Kind_Instance_Name_Attribute => 1568,
-      Iir_Kind_Path_Name_Attribute => 1573,
-      Iir_Kind_Left_Array_Attribute => 1580,
-      Iir_Kind_Right_Array_Attribute => 1587,
-      Iir_Kind_High_Array_Attribute => 1594,
-      Iir_Kind_Low_Array_Attribute => 1601,
-      Iir_Kind_Length_Array_Attribute => 1608,
-      Iir_Kind_Ascending_Array_Attribute => 1615,
-      Iir_Kind_Range_Array_Attribute => 1622,
-      Iir_Kind_Reverse_Range_Array_Attribute => 1629,
-      Iir_Kind_Attribute_Name => 1637
+      Iir_Kind_External_Constant_Name => 1430,
+      Iir_Kind_External_Signal_Name => 1439,
+      Iir_Kind_External_Variable_Name => 1448,
+      Iir_Kind_Package_Pathname => 1452,
+      Iir_Kind_Absolute_Pathname => 1453,
+      Iir_Kind_Relative_Pathname => 1454,
+      Iir_Kind_Pathname_Element => 1458,
+      Iir_Kind_Base_Attribute => 1460,
+      Iir_Kind_Left_Type_Attribute => 1465,
+      Iir_Kind_Right_Type_Attribute => 1470,
+      Iir_Kind_High_Type_Attribute => 1475,
+      Iir_Kind_Low_Type_Attribute => 1480,
+      Iir_Kind_Ascending_Type_Attribute => 1485,
+      Iir_Kind_Image_Attribute => 1491,
+      Iir_Kind_Value_Attribute => 1497,
+      Iir_Kind_Pos_Attribute => 1503,
+      Iir_Kind_Val_Attribute => 1509,
+      Iir_Kind_Succ_Attribute => 1515,
+      Iir_Kind_Pred_Attribute => 1521,
+      Iir_Kind_Leftof_Attribute => 1527,
+      Iir_Kind_Rightof_Attribute => 1533,
+      Iir_Kind_Delayed_Attribute => 1541,
+      Iir_Kind_Stable_Attribute => 1549,
+      Iir_Kind_Quiet_Attribute => 1557,
+      Iir_Kind_Transaction_Attribute => 1565,
+      Iir_Kind_Event_Attribute => 1569,
+      Iir_Kind_Active_Attribute => 1573,
+      Iir_Kind_Last_Event_Attribute => 1577,
+      Iir_Kind_Last_Active_Attribute => 1581,
+      Iir_Kind_Last_Value_Attribute => 1585,
+      Iir_Kind_Driving_Attribute => 1589,
+      Iir_Kind_Driving_Value_Attribute => 1593,
+      Iir_Kind_Behavior_Attribute => 1593,
+      Iir_Kind_Structure_Attribute => 1593,
+      Iir_Kind_Simple_Name_Attribute => 1600,
+      Iir_Kind_Instance_Name_Attribute => 1605,
+      Iir_Kind_Path_Name_Attribute => 1610,
+      Iir_Kind_Left_Array_Attribute => 1617,
+      Iir_Kind_Right_Array_Attribute => 1624,
+      Iir_Kind_High_Array_Attribute => 1631,
+      Iir_Kind_Low_Array_Attribute => 1638,
+      Iir_Kind_Length_Array_Attribute => 1645,
+      Iir_Kind_Ascending_Array_Attribute => 1652,
+      Iir_Kind_Range_Array_Attribute => 1659,
+      Iir_Kind_Reverse_Range_Array_Attribute => 1666,
+      Iir_Kind_Attribute_Name => 1674
      );
 
    function Get_Fields (K : Iir_Kind) return Fields_Array
@@ -4748,6 +4828,12 @@ package body Nodes_Meta is
             return Get_Prefix (N);
          when Field_Signature_Prefix =>
             return Get_Signature_Prefix (N);
+         when Field_External_Pathname =>
+            return Get_External_Pathname (N);
+         when Field_Pathname_Suffix =>
+            return Get_Pathname_Suffix (N);
+         when Field_Pathname_Expression =>
+            return Get_Pathname_Expression (N);
          when Field_Slice_Subtype =>
             return Get_Slice_Subtype (N);
          when Field_Suffix =>
@@ -5108,6 +5194,12 @@ package body Nodes_Meta is
             Set_Prefix (N, V);
          when Field_Signature_Prefix =>
             Set_Signature_Prefix (N, V);
+         when Field_External_Pathname =>
+            Set_External_Pathname (N, V);
+         when Field_Pathname_Suffix =>
+            Set_Pathname_Suffix (N, V);
+         when Field_Pathname_Expression =>
+            Set_Pathname_Expression (N, V);
          when Field_Slice_Subtype =>
             Set_Slice_Subtype (N, V);
          when Field_Suffix =>
@@ -6540,6 +6632,9 @@ package body Nodes_Meta is
            | Iir_Kind_Case_Statement
            | Iir_Kind_Procedure_Call_Statement
            | Iir_Kind_If_Statement
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name
            | Iir_Kind_Delayed_Attribute
            | Iir_Kind_Stable_Attribute
            | Iir_Kind_Quiet_Attribute
@@ -6678,6 +6773,9 @@ package body Nodes_Meta is
            | Iir_Kind_Operator_Symbol
            | Iir_Kind_Selected_By_All_Name
            | Iir_Kind_Parenthesis_Name
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name
            | Iir_Kind_Base_Attribute
            | Iir_Kind_Left_Type_Attribute
            | Iir_Kind_Right_Type_Attribute
@@ -6736,7 +6834,10 @@ package body Nodes_Meta is
            | Iir_Kind_Interface_Variable_Declaration
            | Iir_Kind_Interface_Signal_Declaration
            | Iir_Kind_Interface_File_Declaration
-           | Iir_Kind_Allocator_By_Subtype =>
+           | Iir_Kind_Allocator_By_Subtype
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name =>
             return True;
          when others =>
             return False;
@@ -6829,6 +6930,7 @@ package body Nodes_Meta is
            | Iir_Kind_Selected_Name
            | Iir_Kind_Operator_Symbol
            | Iir_Kind_Selected_By_All_Name
+           | Iir_Kind_Package_Pathname
            | Iir_Kind_Left_Type_Attribute
            | Iir_Kind_Right_Type_Attribute
            | Iir_Kind_High_Type_Attribute
@@ -7023,7 +7125,15 @@ package body Nodes_Meta is
 
    function Has_Shared_Flag (K : Iir_Kind) return Boolean is
    begin
-      return K = Iir_Kind_Variable_Declaration;
+      case K is
+         when Iir_Kind_Variable_Declaration
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name =>
+            return True;
+         when others =>
+            return False;
+      end case;
    end Has_Shared_Flag;
 
    function Has_Design_Unit (K : Iir_Kind) return Boolean is
@@ -7263,6 +7373,8 @@ package body Nodes_Meta is
            | Iir_Kind_Simple_Name
            | Iir_Kind_Selected_Name
            | Iir_Kind_Operator_Symbol
+           | Iir_Kind_Package_Pathname
+           | Iir_Kind_Pathname_Element
            | Iir_Kind_Attribute_Name =>
             return True;
          when others =>
@@ -8300,7 +8412,10 @@ package body Nodes_Meta is
            | Iir_Kind_Case_Statement
            | Iir_Kind_Procedure_Call_Statement
            | Iir_Kind_If_Statement
-           | Iir_Kind_Elsif =>
+           | Iir_Kind_Elsif
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name =>
             return True;
          when others =>
             return False;
@@ -8382,6 +8497,8 @@ package body Nodes_Meta is
            | Iir_Kind_Operator_Symbol
            | Iir_Kind_Selected_By_All_Name
            | Iir_Kind_Parenthesis_Name
+           | Iir_Kind_Package_Pathname
+           | Iir_Kind_Pathname_Element
            | Iir_Kind_Attribute_Name =>
             return True;
          when others =>
@@ -8491,6 +8608,9 @@ package body Nodes_Meta is
            | Iir_Kind_Simple_Name
            | Iir_Kind_Selected_Name
            | Iir_Kind_Selected_By_All_Name
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name
            | Iir_Kind_Left_Type_Attribute
            | Iir_Kind_Right_Type_Attribute
            | Iir_Kind_High_Type_Attribute
@@ -8701,6 +8821,9 @@ package body Nodes_Meta is
            | Iir_Kind_Character_Literal
            | Iir_Kind_Simple_Name
            | Iir_Kind_Selected_Name
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name
            | Iir_Kind_Left_Type_Attribute
            | Iir_Kind_Right_Type_Attribute
            | Iir_Kind_High_Type_Attribute
@@ -8804,6 +8927,36 @@ package body Nodes_Meta is
       return K = Iir_Kind_Signature;
    end Has_Signature_Prefix;
 
+   function Has_External_Pathname (K : Iir_Kind) return Boolean is
+   begin
+      case K is
+         when Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name =>
+            return True;
+         when others =>
+            return False;
+      end case;
+   end Has_External_Pathname;
+
+   function Has_Pathname_Suffix (K : Iir_Kind) return Boolean is
+   begin
+      case K is
+         when Iir_Kind_Package_Pathname
+           | Iir_Kind_Absolute_Pathname
+           | Iir_Kind_Relative_Pathname
+           | Iir_Kind_Pathname_Element =>
+            return True;
+         when others =>
+            return False;
+      end case;
+   end Has_Pathname_Suffix;
+
+   function Has_Pathname_Expression (K : Iir_Kind) return Boolean is
+   begin
+      return K = Iir_Kind_Pathname_Element;
+   end Has_Pathname_Expression;
+
    function Has_Slice_Subtype (K : Iir_Kind) return Boolean is
    begin
       return K = Iir_Kind_Slice_Name;
@@ -9415,7 +9568,10 @@ package body Nodes_Meta is
            | Iir_Kind_Interface_Constant_Declaration
            | Iir_Kind_Interface_Variable_Declaration
            | Iir_Kind_Interface_Signal_Declaration
-           | Iir_Kind_Interface_File_Declaration =>
+           | Iir_Kind_Interface_File_Declaration
+           | Iir_Kind_External_Constant_Name
+           | Iir_Kind_External_Signal_Name
+           | Iir_Kind_External_Variable_Name =>
             return True;
          when others =>
             return False;
diff --git a/src/vhdl/nodes_meta.ads b/src/vhdl/nodes_meta.ads
index 84071fff7..5c740b5fc 100644
--- a/src/vhdl/nodes_meta.ads
+++ b/src/vhdl/nodes_meta.ads
@@ -289,6 +289,9 @@ package Nodes_Meta is
       Field_Name_Staticness,
       Field_Prefix,
       Field_Signature_Prefix,
+      Field_External_Pathname,
+      Field_Pathname_Suffix,
+      Field_Pathname_Expression,
       Field_Slice_Subtype,
       Field_Suffix,
       Field_Index_Subtype,
@@ -770,6 +773,9 @@ package Nodes_Meta is
    function Has_Name_Staticness (K : Iir_Kind) return Boolean;
    function Has_Prefix (K : Iir_Kind) return Boolean;
    function Has_Signature_Prefix (K : Iir_Kind) return Boolean;
+   function Has_External_Pathname (K : Iir_Kind) return Boolean;
+   function Has_Pathname_Suffix (K : Iir_Kind) return Boolean;
+   function Has_Pathname_Expression (K : Iir_Kind) return Boolean;
    function Has_Slice_Subtype (K : Iir_Kind) return Boolean;
    function Has_Suffix (K : Iir_Kind) return Boolean;
    function Has_Index_Subtype (K : Iir_Kind) return Boolean;
diff --git a/src/vhdl/parse.adb b/src/vhdl/parse.adb
index 61df59838..7cb8f825b 100644
--- a/src/vhdl/parse.adb
+++ b/src/vhdl/parse.adb
@@ -882,6 +882,221 @@ package body Parse is
       end loop;
    end Parse_Name_Suffix;
 
+   --  Precond:  next token
+   --  Postcond: next token
+   --
+   --  LRM08 8.7 External names
+   --
+   --  external_pathname ::=
+   --      package_pathname
+   --    | absolute_pathname
+   --    | relative_pathname
+   --
+   --  package_pathname ::=
+   --    @ library_logical_name . package_simple_name .
+   --      { package_simple_name . } object_simple_name
+   --
+   --  absolute_pathname ::=
+   --    . partial_pathname
+   --
+   --  relative_pathname ::=
+   --    { ^ . } partial_pathname
+   --
+   --  partial_pathname ::= { pathname_element . } object_simple_name
+   --
+   --  pathname_element ::=
+   --      entity_simple_name
+   --    | component_instantiation_label
+   --    | block_label
+   --    | generate_statement_label [ ( static_expression ) ]
+   --    | package_simple_name
+   function Parse_External_Pathname return Iir
+   is
+      Res : Iir;
+      Last : Iir;
+      El : Iir;
+   begin
+      case Current_Token is
+         when Tok_Arobase =>
+            Res := Create_Iir (Iir_Kind_Package_Pathname);
+            Set_Location (Res);
+            Last := Res;
+
+            --  Skip '@'
+            Scan;
+
+            if Current_Token /= Tok_Identifier then
+               Error_Msg_Parse ("library name expected after '@'");
+            else
+               Set_Identifier (Res, Current_Identifier);
+
+               --  Skip ident
+               Scan;
+            end if;
+
+            if Current_Token /= Tok_Dot then
+               Error_Msg_Parse ("'.' expected after library name");
+            else
+               --  Skip '.'
+               Scan;
+            end if;
+
+         when Tok_Dot =>
+            Res := Create_Iir (Iir_Kind_Absolute_Pathname);
+            Set_Location (Res);
+            Last := Res;
+
+            --  Skip '.'
+            Scan;
+
+         when Tok_Caret =>
+            Last := Null_Iir;
+            loop
+               El := Create_Iir (Iir_Kind_Relative_Pathname);
+               Set_Location (El);
+
+               --  Skip '^'
+               Scan;
+
+               if Current_Token /= Tok_Dot then
+                  Error_Msg_Parse ("'.' expected after '^'");
+               else
+                  --  Skip '.'
+                  Scan;
+               end if;
+
+               if Last = Null_Iir then
+                  Res := El;
+               else
+                  Set_Pathname_Suffix (Last, El);
+               end if;
+               Last := El;
+
+               exit when Current_Token /= Tok_Caret;
+            end loop;
+
+         when Tok_Identifier =>
+            Last := Null_Iir;
+
+         when others =>
+            Last := Null_Iir;
+            --  Error is handled just below.
+      end case;
+
+      --  Parse pathname elements.
+      loop
+         if Current_Token /= Tok_Identifier then
+            Error_Msg_Parse ("pathname element expected");
+            --  FIXME: resync.
+            return Res;
+         end if;
+
+         El := Create_Iir (Iir_Kind_Pathname_Element);
+         Set_Location (El);
+         Set_Identifier (El, Current_Identifier);
+         if Last = Null_Iir then
+            Res := El;
+         else
+            Set_Pathname_Suffix (Last, El);
+         end if;
+         Last := El;
+
+         --  Skip identifier
+         Scan;
+
+         exit when Current_Token /= Tok_Dot;
+
+         --  Skip '.'
+         Scan;
+      end loop;
+
+      return Res;
+   end Parse_External_Pathname;
+
+   --  Precond:  '<<'
+   --  Postcond: next token
+   --
+   --  LRM08 8.7 External names
+   --  external_name ::=
+   --      external_constant_name
+   --    | external_signal_name
+   --    | external_variable_name
+   --
+   --  external_constant_name ::=
+   --    << CONSTANT external_pathname : subtype_indication >>
+   --
+   --  external_signal_name ::=
+   --   << SIGNAL external_pathname : subtype_indication >>
+   --
+   --  external_variable_name ::=
+   --   << VARIABLE external_pathname : subtype_indication >>
+   function Parse_External_Name return Iir
+   is
+      Loc : Location_Type;
+      Res : Iir;
+      Kind : Iir_Kind;
+   begin
+      Loc := Get_Token_Location;
+
+      --  Skip '<<'
+      Scan;
+
+      case Current_Token is
+         when Tok_Constant =>
+            Kind := Iir_Kind_External_Constant_Name;
+            --  Skip 'constant'
+            Scan;
+         when Tok_Signal =>
+            Kind := Iir_Kind_External_Signal_Name;
+            --  Skip 'signal'
+            Scan;
+         when Tok_Variable =>
+            Kind := Iir_Kind_External_Variable_Name;
+            --  Skip 'variable'
+            Scan;
+         when others =>
+            Error_Msg_Parse
+              ("constant, signal or variable expected after <<");
+            Kind := Iir_Kind_External_Signal_Name;
+      end case;
+
+      Res := Create_Iir (Kind);
+      Set_Location (Res, Loc);
+
+      Set_External_Pathname (Res, Parse_External_Pathname);
+
+      if Current_Token /= Tok_Colon then
+         Error_Msg_Parse ("':' expected after external pathname");
+      else
+         --  Skip ':'
+         Scan;
+      end if;
+
+      Set_Subtype_Indication (Res, Parse_Subtype_Indication);
+
+      if Current_Token /= Tok_Double_Greater then
+         Error_Msg_Parse ("'>>' expected at end of external name");
+      else
+         --  Skip '>>'
+         Scan;
+      end if;
+
+      return Res;
+   end Parse_External_Name;
+
+   --  Precond: next token (identifier, string or '<<')
+   --  Postcond: next token
+   --
+   --  LRM08 8. Names
+   --  name ::=
+   --     simple_name
+   --   | operator_symbol
+   --   | character_literal    --  FIXME: not handled.
+   --   | selected_name
+   --   | indexed_name
+   --   | slice_name
+   --   | attribute_name
+   --   | external_name
    function Parse_Name (Allow_Indexes: Boolean := True) return Iir
    is
       Res: Iir;
@@ -891,20 +1106,29 @@ package body Parse is
             Res := Create_Iir (Iir_Kind_Simple_Name);
             Set_Identifier (Res, Current_Identifier);
             Set_Location (Res);
+
+            --  Skip identifier
+            Scan;
+
          when Tok_String =>
             --  For operator symbol, such as: "+" (A, B).
             Res := Create_Iir (Iir_Kind_String_Literal8);
             Set_String8_Id (Res, Current_String_Id);
             Set_String_Length (Res, Current_String_Length);
             Set_Location (Res);
+
+            --  Skip string
+            Scan;
+         when Tok_Double_Less =>
+            if Vhdl_Std < Vhdl_08 then
+               Error_Msg_Parse ("external name not allowed before vhdl 08");
+            end if;
+            Res := Parse_External_Name;
          when others =>
             Error_Msg_Parse ("identifier expected here");
             raise Parse_Error;
       end case;
 
-      --  Skip identifier or string.
-      Scan;
-
       return Parse_Name_Suffix (Res, Allow_Indexes);
    end Parse_Name;
 
@@ -4192,7 +4416,8 @@ package body Parse is
             Set_Fp_Value (Res, Fp);
             return Res;
 
-         when Tok_Identifier =>
+         when Tok_Identifier
+           | Tok_Double_Less =>
             return Parse_Name (Allow_Indexes => True);
          when Tok_Character =>
             Res := Current_Text;
diff --git a/src/vhdl/scanner.adb b/src/vhdl/scanner.adb
index 544cc74e7..84efbe401 100644
--- a/src/vhdl/scanner.adb
+++ b/src/vhdl/scanner.adb
@@ -1310,7 +1310,7 @@ package body Scanner is
       << Again >> null;
 
       --  Skip commonly used separators.
-      while Source(Pos) = ' ' or Source(Pos) = HT loop
+      while Source (Pos) = ' ' or Source (Pos) = HT loop
          Pos := Pos + 1;
       end loop;
 
@@ -1561,25 +1561,33 @@ package body Scanner is
             end if;
             return;
          when '<' =>
-            if Source (Pos + 1) = '=' then
-               Current_Token := Tok_Less_Equal;
-               Pos := Pos + 2;
-            elsif Source (Pos + 1) = '>' then
-               Current_Token := Tok_Box;
-               Pos := Pos + 2;
-            else
-               Current_Token := Tok_Less;
-               Pos := Pos + 1;
-            end if;
+            case Source (Pos + 1) is
+               when '=' =>
+                  Current_Token := Tok_Less_Equal;
+                  Pos := Pos + 2;
+               when '>' =>
+                  Current_Token := Tok_Box;
+                  Pos := Pos + 2;
+               when '<' =>
+                  Current_Token := Tok_Double_Less;
+                  Pos := Pos + 2;
+               when others =>
+                  Current_Token := Tok_Less;
+                  Pos := Pos + 1;
+            end case;
             return;
          when '>' =>
-            if Source (Pos + 1) = '=' then
-               Current_Token := Tok_Greater_Equal;
-               Pos := Pos + 2;
-            else
-               Current_Token := Tok_Greater;
-               Pos := Pos + 1;
-            end if;
+            case Source (Pos + 1) is
+               when '=' =>
+                  Current_Token := Tok_Greater_Equal;
+                  Pos := Pos + 2;
+               when '>' =>
+                  Current_Token := Tok_Double_Greater;
+                  Pos := Pos + 2;
+               when others =>
+                  Current_Token := Tok_Greater;
+                  Pos := Pos + 1;
+            end case;
             return;
          when '=' =>
             if Source (Pos + 1) = '=' then
@@ -1750,9 +1758,13 @@ package body Scanner is
             Scan_Extended_Identifier;
             return;
          when '^' =>
-            Error_Msg_Scan ("'^' is not a VHDL operator, use 'xor'");
+            if Vhdl_Std >= Vhdl_08 then
+               Current_Token := Tok_Caret;
+            else
+               Current_Token := Tok_Xor;
+               Error_Msg_Scan ("'^' is not a VHDL operator, use 'xor'");
+            end if;
             Pos := Pos + 1;
-            Current_Token := Tok_Xor;
             return;
          when '~' =>
             Error_Msg_Scan ("'~' is not a VHDL operator, use 'not'");
@@ -1807,7 +1819,7 @@ package body Scanner is
             Pos := Pos + 1;
             goto Again;
          when '@' =>
-            if Flag_Psl then
+            if Vhdl_Std >= Vhdl_08 or Flag_Psl then
                Current_Token := Tok_Arobase;
                Pos := Pos + 1;
                return;
diff --git a/src/vhdl/sem_expr.adb b/src/vhdl/sem_expr.adb
index c8722b66a..bbc9aaa22 100644
--- a/src/vhdl/sem_expr.adb
+++ b/src/vhdl/sem_expr.adb
@@ -393,6 +393,8 @@ package body Sem_Expr is
            | Iir_Kind_Unit_Declaration
            | Iir_Kind_Enumeration_Literal =>
             return Expr;
+         when Iir_Kinds_External_Name =>
+            return Expr;
          when Iir_Kinds_Object_Declaration
            | Iir_Kind_Aggregate
            | Iir_Kind_Allocator_By_Expression
@@ -3826,6 +3828,8 @@ package body Sem_Expr is
                return;
             when Iir_Kinds_Quantity_Declaration =>
                return;
+            when Iir_Kinds_External_Name =>
+               return;
             when Iir_Kind_File_Declaration
               | Iir_Kind_Interface_File_Declaration =>
                --  LRM 4.3.2  Interface declarations
@@ -4004,6 +4008,10 @@ package body Sem_Expr is
                return E;
             end;
 
+         when Iir_Kinds_External_Name =>
+            Sem_External_Name (Expr);
+            return Expr;
+
          when Iir_Kinds_Monadic_Operator =>
             return Sem_Operator (Expr, A_Type, 1);
 
diff --git a/src/vhdl/sem_names.adb b/src/vhdl/sem_names.adb
index 66bd04838..478499da5 100644
--- a/src/vhdl/sem_names.adb
+++ b/src/vhdl/sem_names.adb
@@ -2415,6 +2415,7 @@ package body Sem_Names is
            | Iir_Kind_Implicit_Dereference
            | Iir_Kind_Selected_Element
            | Iir_Kind_Attribute_Value
+           | Iir_Kind_Simple_Name_Attribute
            | Iir_Kind_Function_Call =>
             Add_Result (Res, Sem_As_Indexed_Or_Slice_Name (Prefix, True));
 
@@ -3883,6 +3884,24 @@ package body Sem_Names is
       end case;
    end Sem_Denoting_Name;
 
+   procedure Sem_External_Name (Name : Iir)
+   is
+      Atype : Iir;
+   begin
+      pragma Assert (Get_Type (Name) = Null_Iir);
+
+      Atype := Get_Subtype_Indication (Name);
+
+      Atype := Sem_Types.Sem_Subtype_Indication (Atype);
+      Set_Subtype_Indication (Name, Atype);
+      Atype := Get_Type_Of_Subtype_Indication (Atype);
+      if Atype = Null_Iir then
+         Atype := Create_Error_Type (Null_Iir);
+      end if;
+
+      Set_Type (Name, Atype);
+   end Sem_External_Name;
+
    function Sem_Terminal_Name (Name : Iir) return Iir
    is
       Res : Iir;
diff --git a/src/vhdl/sem_names.ads b/src/vhdl/sem_names.ads
index 3bc85305d..3ce4acf74 100644
--- a/src/vhdl/sem_names.ads
+++ b/src/vhdl/sem_names.ads
@@ -151,6 +151,9 @@ package Sem_Names is
    --  Like Sem_Denoting_Name but expect a terminal name.
    function Sem_Terminal_Name (Name : Iir) return Iir;
 
+   --  Analyze an external name.
+   procedure Sem_External_Name (Name : Iir);
+
    --  Emit an error for NAME that doesn't match its class CLASS_NAME.
    procedure Error_Class_Match (Name : Iir; Class_Name : String);
 
diff --git a/src/vhdl/tokens.adb b/src/vhdl/tokens.adb
index e1bdfefaa..97062b72b 100644
--- a/src/vhdl/tokens.adb
+++ b/src/vhdl/tokens.adb
@@ -113,6 +113,13 @@ package body Tokens is
          when Tok_Condition =>
             return "??";
 
+         when Tok_Double_Less =>
+            return "<<";
+         when Tok_Double_Greater =>
+            return ">>";
+         when Tok_Caret =>
+            return "^";
+
          -- multiplying operator
          when Tok_Star =>
             return "*";
diff --git a/src/vhdl/tokens.ads b/src/vhdl/tokens.ads
index fc4b77f82..aaabaa650 100644
--- a/src/vhdl/tokens.ads
+++ b/src/vhdl/tokens.ads
@@ -79,7 +79,11 @@ package Tokens is
    -- and adding_operator
        Tok_Ampersand,           -- &
 
+   --  VHDL 2008
        Tok_Condition,           -- ??
+       Tok_Double_Less,         -- <<
+       Tok_Double_Greater,      -- >>
+       Tok_Caret,               -- ^
 
    --  PSL
        Tok_And_And,             -- &&