vhdl 2008: allow to read out ports.

2 files changed, 30 insertions, 8 deletions

diff --git a/src/grt/grt-signals.adb b/src/grt/grt-signals.adb
index 7f8d3a0..38d33c8 100644
--- a/src/grt/grt-signals.adb
+++ b/src/grt/grt-signals.adb
@@ -1954,10 +1954,10 @@ package body Grt.Signals is
    begin
       case Sig.S.Mode_Sig is
          when Mode_Signal
-           | Mode_Buffer =>
-            return True;
-         when Mode_Linkage
+           | Mode_Buffer
            | Mode_Out =>
+            return True;
+         when Mode_Linkage =>
             --  No effective value.
             return False;
          when Mode_Inout
@@ -2150,11 +2150,11 @@ package body Grt.Signals is
 
       case Sig.S.Mode_Sig is
          when Mode_Signal
-           | Mode_Buffer =>
+           | Mode_Buffer
+           | Mode_Out =>
             --  Effective value is driving value.
             Sig.Flags.Propag := Propag_Done;
-         when Mode_Linkage
-           | Mode_Out =>
+         when Mode_Linkage =>
             --  No effective value.
             Sig.Flags.Propag := Propag_Done;
          when Mode_Inout
diff --git a/src/vhdl/sem_expr.adb b/src/vhdl/sem_expr.adb
index 703c554..46e75f3 100644
--- a/src/vhdl/sem_expr.adb
+++ b/src/vhdl/sem_expr.adb
@@ -3697,9 +3697,31 @@ package body Sem_Expr is
                   when Iir_In_Mode
                     | Iir_Inout_Mode
                     | Iir_Buffer_Mode =>
+                     --  LRM08 6.5.3 Interface object declarations
+                     --  - in. The value of the interface object is allowed
+                     --     to be read, [...]
+                     --  - inout or buffer.  Reading and updating the value of
+                     --     the interface object is allowed. [...]
                      null;
-                  when Iir_Out_Mode
-                    | Iir_Linkage_Mode =>
+                  when Iir_Out_Mode =>
+                     --  LRM08 6.5.3 Interface object declarations
+                     --  - out. The value of the interface object is allowed
+                     --    [to be updated and,]  provided it is not a signal
+                     --    parameter, read.
+                     if Vhdl_Std < Vhdl_08
+                       or else (Get_Kind (Get_Parent (Obj)) in
+                                  Iir_Kinds_Subprogram_Declaration)
+                     then
+                        Error_Msg_Sem
+                          (Disp_Node (Obj) & " cannot be read", Expr);
+                     end if;
+                  when Iir_Linkage_Mode =>
+                     --  LRM08 6.5.3 Interface object declarations
+                     --  - linkage.  Reading and updating the value of the
+                     --    interface object is allowed, but only by appearing
+                     --    as an actual corresponding to an interface object
+                     --    of mode LINKAGE.  No other reading or updating is
+                     --    permitted.
                      Error_Msg_Sem (Disp_Node (Obj) & " cannot be read", Expr);
                   when Iir_Unknown_Mode =>
                      raise Internal_Error;