ams-vhdl: improve error recovery

6 files changed, 92 insertions, 61 deletions

diff --git a/src/vhdl/vhdl-nodes.ads b/src/vhdl/vhdl-nodes.ads
index dd90d12d1..9a6e671e1 100644
--- a/src/vhdl/vhdl-nodes.ads
+++ b/src/vhdl/vhdl-nodes.ads
@@ -4617,6 +4617,7 @@ package Vhdl.Nodes is
    -- Iir_Kind_Error (Short)
    --  Can be used instead of an expression or a type.
    --   Get/Set_Type (Field1)
+   --   Get/Set_Nature (Alias Field1)
    --
    --   Get/Set_Error_Origin (Field2)
    --
diff --git a/src/vhdl/vhdl-nodes_meta.adb b/src/vhdl/vhdl-nodes_meta.adb
index de6b46488..206716ae7 100644
--- a/src/vhdl/vhdl-nodes_meta.adb
+++ b/src/vhdl/vhdl-nodes_meta.adb
@@ -8434,7 +8434,8 @@ package body Vhdl.Nodes_Meta is
    function Has_Nature (K : Iir_Kind) return Boolean is
    begin
       case K is
-         when Iir_Kind_Nature_Declaration
+         when Iir_Kind_Error
+           | Iir_Kind_Nature_Declaration
            | Iir_Kind_Subnature_Declaration
            | Iir_Kind_Nature_Element_Declaration
            | Iir_Kind_Terminal_Declaration
diff --git a/src/vhdl/vhdl-parse.adb b/src/vhdl/vhdl-parse.adb
index 39dc4ee68..e17846618 100644
--- a/src/vhdl/vhdl-parse.adb
+++ b/src/vhdl/vhdl-parse.adb
@@ -9110,7 +9110,8 @@ package body Vhdl.Parse is
       Expect_Scan (Tok_End);
 
       --  Skip 'procedural'.
-      Expect_Scan (Tok_Procedural);
+      Expect_Scan (Tok_Procedural, "missing 'procedural' after 'end'");
+      Set_End_Has_Reserved_Id (Res, True);
 
       Check_End_Name (Res);
 
diff --git a/src/vhdl/vhdl-sem_decls.adb b/src/vhdl/vhdl-sem_decls.adb
index 23458bd35..d30fd6e85 100644
--- a/src/vhdl/vhdl-sem_decls.adb
+++ b/src/vhdl/vhdl-sem_decls.adb
@@ -2090,7 +2090,7 @@ package body Vhdl.Sem_Decls is
       end if;
    end Sem_Terminal_Declaration;
 
-   procedure Sem_Branch_Quantity_Declaration (Decl : Iir; Last_Decl : Iir)
+   procedure Sem_Branch_Quantity_Declaration (Decl : Iir; Prev_Decl : Iir)
    is
       Plus_Name : Iir;
       Minus_Name : Iir;
@@ -2106,9 +2106,15 @@ package body Vhdl.Sem_Decls is
       if Plus_Name = Null_Iir then
          --  List of identifier.
          Is_Second := True;
-         Plus_Name := Get_Plus_Terminal (Last_Decl);
-         Minus_Name := Get_Minus_Terminal (Last_Decl);
-         Value := Get_Default_Value (Last_Decl);
+         Plus_Name := Get_Plus_Terminal (Prev_Decl);
+         Minus_Name := Get_Minus_Terminal (Prev_Decl);
+         if Get_Kind (Decl) = Get_Kind (Prev_Decl) then
+            --  Keep the same default value for all across and all through.
+            Value := Get_Default_Value (Prev_Decl);
+         else
+            --  But do not use the across default value for through quantity.
+            Value := Get_Default_Value (Decl);
+         end if;
       else
          Is_Second := False;
          Plus_Name := Sem_Terminal_Name (Plus_Name);
@@ -2129,68 +2135,79 @@ package body Vhdl.Sem_Decls is
             --
             --  GHDL: FIXME: isn't it self-referential with the definition of
             --  the terminal nature ?
-            Minus_Name := Get_Reference
-              (Get_Nature_Simple_Nature (Get_Nature (Plus_Name)));
+            if Is_Error (Plus_Name) then
+               Minus_Name := Error_Mark;
+            else
+               Minus_Name := Get_Reference
+                 (Get_Nature_Simple_Nature (Get_Nature (Plus_Name)));
+            end if;
          end if;
          Value := Get_Default_Value (Decl);
       end if;
       Set_Plus_Terminal (Decl, Plus_Name);
       Set_Minus_Terminal (Decl, Minus_Name);
 
-      declare
-         Plus_Nature : constant Iir := Get_Nature (Plus_Name);
-         Minus_Nature : constant Iir := Get_Nature (Minus_Name);
-         Plus_Composite : constant Boolean :=
-           Is_Composite_Nature (Plus_Nature);
-         Minus_Composite : constant Boolean :=
-           Is_Composite_Nature (Minus_Nature);
-      begin
-         --  AMS-LRM17 6.4.2.7 Quantity declarations
-         --  If the terminals denoted by the terminal names of a terminal
-         --  aspect are both of composite natures, then they shall be of the
-         --  same nature, [and for each element of the plus terminal there
-         --  shall be a matching element of the minus terminal.]
-         --  If one terminal is a terminal of a composite nature and the
-         --  other of a scalar nature, then the scalar nature nature shall be
-         --  the nature of the scalar subelements of the composite terminal.
-         if (Plus_Composite and Minus_Composite)
-           or else (not Plus_Composite and not Minus_Composite)
-         then
-            if Get_Base_Nature (Plus_Nature) /= Get_Base_Nature (Minus_Nature)
-            then
-               Error_Msg_Sem
-                 (+Decl, "terminals must be of the same nature");
-            end if;
-            Nat := Plus_Nature;
-         elsif Plus_Composite then
-            pragma Assert (not Minus_Composite);
-            if (Get_Nature_Simple_Nature (Plus_Nature)
-                  /= Get_Base_Nature (Minus_Nature))
-            then
-               Error_Msg_Sem
-                 (+Decl, "minus terminal must be of the nature of "
-                    & "plus subelements");
-            end if;
-            Nat := Plus_Nature;
-         else
-            pragma Assert (Minus_Composite and not Plus_Composite);
-            if (Get_Nature_Simple_Nature (Minus_Nature)
-                  /= Get_Base_Nature (Plus_Nature))
+      if not Is_Error (Plus_Name) and then not Is_Error (Minus_Name) then
+         declare
+            Plus_Nature : constant Iir := Get_Nature (Plus_Name);
+            Minus_Nature : constant Iir := Get_Nature (Minus_Name);
+            Plus_Composite : constant Boolean :=
+              Is_Composite_Nature (Plus_Nature);
+            Minus_Composite : constant Boolean :=
+              Is_Composite_Nature (Minus_Nature);
+         begin
+            --  AMS-LRM17 6.4.2.7 Quantity declarations
+            --  If the terminals denoted by the terminal names of a terminal
+            --  aspect are both of composite natures, then they shall be of the
+            --  same nature, [and for each element of the plus terminal there
+            --  shall be a matching element of the minus terminal.]
+            --  If one terminal is a terminal of a composite nature and the
+            --  other of a scalar nature, then the scalar nature nature shall
+            --  be the nature of the scalar subelements of the composite
+            --  terminal.
+            if (Plus_Composite and Minus_Composite)
+              or else (not Plus_Composite and not Minus_Composite)
             then
-               Error_Msg_Sem
-                 (+Decl, "plus terminal must be of the nature of "
-                    & "minus subelements");
+               if (Get_Base_Nature (Plus_Nature)
+                     /= Get_Base_Nature (Minus_Nature))
+               then
+                  Error_Msg_Sem
+                    (+Decl, "terminals must be of the same nature");
+               end if;
+               Nat := Plus_Nature;
+            elsif Plus_Composite then
+               pragma Assert (not Minus_Composite);
+               if (Get_Nature_Simple_Nature (Plus_Nature)
+                     /= Get_Base_Nature (Minus_Nature))
+               then
+                  Error_Msg_Sem
+                    (+Decl, "minus terminal must be of the nature of "
+                       & "plus subelements");
+               end if;
+               Nat := Plus_Nature;
+            else
+               pragma Assert (Minus_Composite and not Plus_Composite);
+               if (Get_Nature_Simple_Nature (Minus_Nature)
+                     /= Get_Base_Nature (Plus_Nature))
+               then
+                  Error_Msg_Sem
+                    (+Decl, "plus terminal must be of the nature of "
+                       & "minus subelements");
+               end if;
+               Nat := Minus_Nature;
             end if;
-            Nat := Minus_Nature;
-         end if;
-      end;
-      case Iir_Kinds_Branch_Quantity_Declaration (Get_Kind (Decl)) is
-         when Iir_Kind_Across_Quantity_Declaration =>
-            Branch_Type := Get_Across_Type (Nat);
-         when Iir_Kind_Through_Quantity_Declaration =>
-            Branch_Type := Get_Through_Type (Nat);
-      end case;
-      pragma Assert (Branch_Type /= Null_Iir);
+         end;
+
+         case Iir_Kinds_Branch_Quantity_Declaration (Get_Kind (Decl)) is
+            when Iir_Kind_Across_Quantity_Declaration =>
+               Branch_Type := Get_Across_Type (Nat);
+            when Iir_Kind_Through_Quantity_Declaration =>
+               Branch_Type := Get_Through_Type (Nat);
+         end case;
+         pragma Assert (Branch_Type /= Null_Iir);
+      else
+         Branch_Type := Error_Mark;
+      end if;
       Set_Type (Decl, Branch_Type);
 
       Set_Name_Staticness (Decl, Locally);
diff --git a/src/vhdl/vhdl-sem_stmts.adb b/src/vhdl/vhdl-sem_stmts.adb
index e1cb740b6..98e01ccb3 100644
--- a/src/vhdl/vhdl-sem_stmts.adb
+++ b/src/vhdl/vhdl-sem_stmts.adb
@@ -2107,6 +2107,7 @@ package body Vhdl.Sem_Stmts is
    procedure Sem_Simple_Simultaneous_Statement (Stmt : Iir)
    is
       Left, Right : Iir;
+      Left_Type, Right_Type : Iir;
       Res_Type : Iir;
    begin
       Left := Get_Simultaneous_Left (Stmt);
@@ -2120,6 +2121,12 @@ package body Vhdl.Sem_Stmts is
          return;
       end if;
 
+      Left_Type := Get_Type (Left);
+      Right_Type := Get_Type (Right);
+      if Left_Type = Null_Iir or else Right_Type = Null_Iir then
+         return;
+      end if;
+
       Res_Type := Search_Compatible_Type (Get_Type (Left), Get_Type (Right));
       if Res_Type = Null_Iir then
          Error_Msg_Sem
diff --git a/src/vhdl/vhdl-sem_types.adb b/src/vhdl/vhdl-sem_types.adb
index 6e9b87928..c02e682a8 100644
--- a/src/vhdl/vhdl-sem_types.adb
+++ b/src/vhdl/vhdl-sem_types.adb
@@ -2715,7 +2715,9 @@ package body Vhdl.Sem_Types is
 
    function Is_Nature_Type (Dtype : Iir) return Boolean is
    begin
-      case Iir_Kinds_Type_And_Subtype_Definition (Get_Kind (Dtype)) is
+      case Get_Kind (Dtype) is
+         when Iir_Kind_Error =>
+            return True;
          when Iir_Kind_Floating_Type_Definition
            | Iir_Kind_Floating_Subtype_Definition =>
             return True;
@@ -2751,6 +2753,8 @@ package body Vhdl.Sem_Types is
            | Iir_Kind_Enumeration_Subtype_Definition
            | Iir_Kind_Enumeration_Type_Definition =>
             return False;
+         when others =>
+            Error_Kind ("is_nature_type", Dtype);
       end case;
    end Is_Nature_Type;