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-rw-r--r--src/vhdl/sem_expr.adb113
1 files changed, 80 insertions, 33 deletions
diff --git a/src/vhdl/sem_expr.adb b/src/vhdl/sem_expr.adb
index da2a890d3..b2f4a4d99 100644
--- a/src/vhdl/sem_expr.adb
+++ b/src/vhdl/sem_expr.adb
@@ -3717,6 +3717,83 @@ package body Sem_Expr is
return Expr;
end Sem_Qualified_Expression;
+ function Is_Signal_Parameter (Obj : Iir) return Boolean is
+ begin
+ return Get_Kind (Obj) = Iir_Kind_Interface_Signal_Declaration
+ and then
+ Get_Kind (Get_Parent (Obj)) in Iir_Kinds_Subprogram_Declaration;
+ end Is_Signal_Parameter;
+
+ function Can_Interface_Be_Read (Inter : Iir) return Boolean is
+ begin
+ case Get_Mode (Inter) 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 =>
+ -- LRM93 4.3.2 Interface declarations
+ -- - out. The value of the interface object is allowed to be
+ -- updated, but it must not be read.
+ --
+ -- 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 Is_Signal_Parameter (Inter) then
+ return False;
+ 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.
+ return False;
+ when Iir_Unknown_Mode =>
+ raise Internal_Error;
+ end case;
+ return True;
+ end Can_Interface_Be_Read;
+
+ function Can_Interface_Be_Updated (Inter : Iir) return Boolean is
+ begin
+ case Get_Mode (Inter) is
+ when Iir_In_Mode =>
+ -- LRM08 6.5.3 Interface object declarations
+ -- - in. The value of the interface object is allowed to be read,
+ -- but it shall not be updated.
+ return False;
+ when Iir_Out_Mode =>
+ -- LRM08 6.5.3 Interface object declarations
+ -- - out. The value of the interface object is allowed
+ -- to be updated [and, ...]
+ return True;
+ when Iir_Inout_Mode
+ | Iir_Buffer_Mode =>
+ -- LRM08 6.5.3 Interface object declarations
+ -- - inout or buffer. Reading and updating the value of the
+ -- interface is allowed.
+ return True;
+ 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.
+ return False;
+ when Iir_Unknown_Mode =>
+ raise Internal_Error;
+ end case;
+ end Can_Interface_Be_Updated;
+
procedure Check_Read_Aggregate (Aggr : Iir)
is
pragma Unreferenced (Aggr);
@@ -3758,39 +3835,9 @@ package body Sem_Expr is
Obj := Get_Name (Obj);
when Iir_Kind_Interface_Signal_Declaration
| Iir_Kind_Interface_Variable_Declaration =>
- case Get_Mode (Obj) 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 =>
- -- 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;
- end case;
+ if not Can_Interface_Be_Read (Obj) then
+ Error_Msg_Sem (Disp_Node (Obj) & " cannot be read", Expr);
+ end if;
return;
when Iir_Kind_Enumeration_Literal
| Iir_Kind_Physical_Int_Literal