diff options
| -rw-r--r-- | src/vhdl/vhdl-evaluation.adb | 62 |
1 files changed, 60 insertions, 2 deletions
diff --git a/src/vhdl/vhdl-evaluation.adb b/src/vhdl/vhdl-evaluation.adb index 6a714a330..babd3fef6 100644 --- a/src/vhdl/vhdl-evaluation.adb +++ b/src/vhdl/vhdl-evaluation.adb @@ -338,7 +338,6 @@ package body Vhdl.Evaluation is Error_Msg_Sem (+A_Range, "range length is beyond subtype length"); Right := Left; else - -- FIXME: what about nul range? Right := Build_Discrete (Pos, A_Range); Set_Literal_Origin (Right, Null_Iir); Set_Right_Limit_Expr (A_Range, Right); @@ -346,6 +345,58 @@ package body Vhdl.Evaluation is Set_Right_Limit (A_Range, Right); end Set_Right_Limit_By_Length; + procedure Set_Enumeration_Null_Range_Limits (A_Range : Iir) + is + A_Type : constant Iir := Get_Type (A_Range); + Btype : constant Iir := Get_Base_Type (A_Type); + Enum_List : constant Iir_Flist := Get_Enumeration_Literal_List (Btype); + Last_Enum : constant Natural := Flist_Last (Enum_List); + Left : constant Iir := Get_Left_Limit (A_Range); + Right : Iir; + Pos : Int64; + Invert : Boolean; + begin + pragma Assert (Get_Expr_Staticness (A_Range) = Locally); + + if Last_Enum = 0 then + Error_Msg_Sem + (+A_Range, "null range not supported for enumeration type %n", + +A_Type); + Right := Left; + else + Pos := Eval_Pos (Left); + Invert := False; + case Get_Direction (A_Range) is + when Dir_To => + if Pos = 0 then + Pos := Pos + 1; + Invert := True; + else + Pos := Pos - 1; + end if; + when Dir_Downto => + if Pos = Int64 (Last_Enum) then + Pos := Pos - 1; + Invert := True; + else + Pos := Pos + 1; + end if; + end case; + + Right := Build_Discrete (Pos, A_Range); + Set_Literal_Origin (Right, Null_Iir); + + if Invert then + Set_Left_Limit_Expr (A_Range, Right); + Set_Left_Limit (A_Range, Right); + Set_Right_Limit (A_Range, Left); + else + Set_Right_Limit_Expr (A_Range, Right); + Set_Right_Limit (A_Range, Right); + end if; + end if; + end Set_Enumeration_Null_Range_Limits; + -- Create a range of type A_TYPE whose length is LEN. -- Note: only two nodes are created: -- * the range_expression (node returned) @@ -369,7 +420,14 @@ package body Vhdl.Evaluation is Set_Type (Constraint, A_Type); Set_Left_Limit (Constraint, Get_Left_Limit (Index_Constraint)); Set_Direction (Constraint, Get_Direction (Index_Constraint)); - Set_Right_Limit_By_Length (Constraint, Len); + if Len = 0 + and then (Get_Kind (Get_Base_Type (A_Type)) + = Iir_Kind_Enumeration_Type_Definition) + then + Set_Enumeration_Null_Range_Limits (Constraint); + else + Set_Right_Limit_By_Length (Constraint, Len); + end if; return Constraint; end Create_Range_By_Length; |