Rework of overload resolution in implicit conversions.

Fix tiket 81.

6 files changed, 110 insertions, 147 deletions

diff --git a/src/vhdl/iirs.adb b/src/vhdl/iirs.adb
index 609d9fd21..ac25a832c 100644
--- a/src/vhdl/iirs.adb
+++ b/src/vhdl/iirs.adb
@@ -4026,22 +4026,6 @@ package body Iirs is
       Set_State1 (Target, Iir_Staticness'Pos (Static));
    end Set_Expr_Staticness;
 
-   function Get_Has_Implicit_Conversion (Expr : Iir) return Boolean is
-   begin
-      pragma Assert (Expr /= Null_Iir);
-      pragma Assert (Has_Has_Implicit_Conversion (Get_Kind (Expr)),
-                     "no field Has_Implicit_Conversion");
-      return Get_Flag1 (Expr);
-   end Get_Has_Implicit_Conversion;
-
-   procedure Set_Has_Implicit_Conversion (Expr : Iir; Flag : Boolean) is
-   begin
-      pragma Assert (Expr /= Null_Iir);
-      pragma Assert (Has_Has_Implicit_Conversion (Get_Kind (Expr)),
-                     "no field Has_Implicit_Conversion");
-      Set_Flag1 (Expr, Flag);
-   end Set_Has_Implicit_Conversion;
-
    function Get_Error_Origin (Target : Iir) return Iir is
    begin
       pragma Assert (Target /= Null_Iir);
diff --git a/src/vhdl/iirs.ads b/src/vhdl/iirs.ads
index e8a1b74ec..0db83caec 100644
--- a/src/vhdl/iirs.ads
+++ b/src/vhdl/iirs.ads
@@ -2980,8 +2980,6 @@ package Iirs is
    --   Get/Set_Expr_Staticness (State1)
    --
    --   Get/Set_Name_Staticness (State2)
-   --
-   --   Get/Set_Has_Implicit_Conversion (Flag1)
 
    -- Iir_Kind_Aggregate (Short)
    --
@@ -6142,13 +6140,6 @@ package Iirs is
    function Get_Expr_Staticness (Target : Iir) return Iir_Staticness;
    procedure Set_Expr_Staticness (Target : Iir; Static : Iir_Staticness);
 
-   --  Set when EXPR has implicit conversion in its sub-tree.  This is used
-   --  only during analysis for overload resolution (see LRM08 9.3.6 Type
-   --  conversions).
-   --  Field: Flag1
-   function Get_Has_Implicit_Conversion (Expr : Iir) return Boolean;
-   procedure Set_Has_Implicit_Conversion (Expr : Iir; Flag : Boolean);
-
    --  Node which couldn't be correctly analyzed.
    --  Field: Field2
    function Get_Error_Origin (Target : Iir) return Iir;
diff --git a/src/vhdl/nodes_meta.adb b/src/vhdl/nodes_meta.adb
index cbe86fbc3..c93582571 100644
--- a/src/vhdl/nodes_meta.adb
+++ b/src/vhdl/nodes_meta.adb
@@ -238,7 +238,6 @@ package body Nodes_Meta is
       Field_Named_Entity => Type_Iir,
       Field_Alias_Declaration => Type_Iir,
       Field_Expr_Staticness => Type_Iir_Staticness,
-      Field_Has_Implicit_Conversion => Type_Boolean,
       Field_Error_Origin => Type_Iir,
       Field_Operand => Type_Iir,
       Field_Left => Type_Iir,
@@ -763,8 +762,6 @@ package body Nodes_Meta is
             return "alias_declaration";
          when Field_Expr_Staticness =>
             return "expr_staticness";
-         when Field_Has_Implicit_Conversion =>
-            return "has_implicit_conversion";
          when Field_Error_Origin =>
             return "error_origin";
          when Field_Operand =>
@@ -1865,8 +1862,6 @@ package body Nodes_Meta is
             return Attr_None;
          when Field_Expr_Staticness =>
             return Attr_None;
-         when Field_Has_Implicit_Conversion =>
-            return Attr_None;
          when Field_Error_Origin =>
             return Attr_None;
          when Field_Operand =>
@@ -3238,7 +3233,6 @@ package body Nodes_Meta is
       Field_Type,
       Field_Implementation,
       --  Iir_Kind_Function_Call
-      Field_Has_Implicit_Conversion,
       Field_Expr_Staticness,
       Field_Name_Staticness,
       Field_Prefix,
@@ -3683,7 +3677,6 @@ package body Nodes_Meta is
       Field_Identifier,
       Field_Pathname_Suffix,
       Field_Named_Entity,
-      Field_Base_Name,
       --  Iir_Kind_Absolute_Pathname
       Field_Pathname_Suffix,
       --  Iir_Kind_Relative_Pathname
@@ -4105,102 +4098,102 @@ package body Nodes_Meta is
       Iir_Kind_Modulus_Operator => 1049,
       Iir_Kind_Remainder_Operator => 1054,
       Iir_Kind_Exponentiation_Operator => 1059,
-      Iir_Kind_Function_Call => 1068,
-      Iir_Kind_Aggregate => 1074,
-      Iir_Kind_Parenthesis_Expression => 1077,
-      Iir_Kind_Qualified_Expression => 1081,
-      Iir_Kind_Type_Conversion => 1086,
-      Iir_Kind_Allocator_By_Expression => 1090,
-      Iir_Kind_Allocator_By_Subtype => 1094,
-      Iir_Kind_Selected_Element => 1100,
-      Iir_Kind_Dereference => 1105,
-      Iir_Kind_Implicit_Dereference => 1110,
-      Iir_Kind_Slice_Name => 1117,
-      Iir_Kind_Indexed_Name => 1123,
-      Iir_Kind_Psl_Expression => 1125,
-      Iir_Kind_Sensitized_Process_Statement => 1145,
-      Iir_Kind_Process_Statement => 1164,
-      Iir_Kind_Concurrent_Conditional_Signal_Assignment => 1175,
-      Iir_Kind_Concurrent_Selected_Signal_Assignment => 1187,
-      Iir_Kind_Concurrent_Assertion_Statement => 1195,
-      Iir_Kind_Psl_Default_Clock => 1199,
-      Iir_Kind_Psl_Assert_Statement => 1208,
-      Iir_Kind_Psl_Cover_Statement => 1217,
-      Iir_Kind_Concurrent_Procedure_Call_Statement => 1223,
-      Iir_Kind_Block_Statement => 1236,
-      Iir_Kind_If_Generate_Statement => 1246,
-      Iir_Kind_For_Generate_Statement => 1255,
-      Iir_Kind_Component_Instantiation_Statement => 1265,
-      Iir_Kind_Simple_Simultaneous_Statement => 1272,
-      Iir_Kind_Generate_Statement_Body => 1283,
-      Iir_Kind_If_Generate_Else_Clause => 1288,
-      Iir_Kind_Signal_Assignment_Statement => 1297,
-      Iir_Kind_Null_Statement => 1301,
-      Iir_Kind_Assertion_Statement => 1308,
-      Iir_Kind_Report_Statement => 1314,
-      Iir_Kind_Wait_Statement => 1321,
-      Iir_Kind_Variable_Assignment_Statement => 1327,
-      Iir_Kind_Return_Statement => 1333,
-      Iir_Kind_For_Loop_Statement => 1341,
-      Iir_Kind_While_Loop_Statement => 1348,
-      Iir_Kind_Next_Statement => 1354,
-      Iir_Kind_Exit_Statement => 1360,
-      Iir_Kind_Case_Statement => 1367,
-      Iir_Kind_Procedure_Call_Statement => 1372,
-      Iir_Kind_If_Statement => 1380,
-      Iir_Kind_Elsif => 1385,
-      Iir_Kind_Character_Literal => 1392,
-      Iir_Kind_Simple_Name => 1399,
-      Iir_Kind_Selected_Name => 1407,
-      Iir_Kind_Operator_Symbol => 1412,
-      Iir_Kind_Selected_By_All_Name => 1417,
-      Iir_Kind_Parenthesis_Name => 1421,
-      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
+      Iir_Kind_Function_Call => 1067,
+      Iir_Kind_Aggregate => 1073,
+      Iir_Kind_Parenthesis_Expression => 1076,
+      Iir_Kind_Qualified_Expression => 1080,
+      Iir_Kind_Type_Conversion => 1085,
+      Iir_Kind_Allocator_By_Expression => 1089,
+      Iir_Kind_Allocator_By_Subtype => 1093,
+      Iir_Kind_Selected_Element => 1099,
+      Iir_Kind_Dereference => 1104,
+      Iir_Kind_Implicit_Dereference => 1109,
+      Iir_Kind_Slice_Name => 1116,
+      Iir_Kind_Indexed_Name => 1122,
+      Iir_Kind_Psl_Expression => 1124,
+      Iir_Kind_Sensitized_Process_Statement => 1144,
+      Iir_Kind_Process_Statement => 1163,
+      Iir_Kind_Concurrent_Conditional_Signal_Assignment => 1174,
+      Iir_Kind_Concurrent_Selected_Signal_Assignment => 1186,
+      Iir_Kind_Concurrent_Assertion_Statement => 1194,
+      Iir_Kind_Psl_Default_Clock => 1198,
+      Iir_Kind_Psl_Assert_Statement => 1207,
+      Iir_Kind_Psl_Cover_Statement => 1216,
+      Iir_Kind_Concurrent_Procedure_Call_Statement => 1222,
+      Iir_Kind_Block_Statement => 1235,
+      Iir_Kind_If_Generate_Statement => 1245,
+      Iir_Kind_For_Generate_Statement => 1254,
+      Iir_Kind_Component_Instantiation_Statement => 1264,
+      Iir_Kind_Simple_Simultaneous_Statement => 1271,
+      Iir_Kind_Generate_Statement_Body => 1282,
+      Iir_Kind_If_Generate_Else_Clause => 1287,
+      Iir_Kind_Signal_Assignment_Statement => 1296,
+      Iir_Kind_Null_Statement => 1300,
+      Iir_Kind_Assertion_Statement => 1307,
+      Iir_Kind_Report_Statement => 1313,
+      Iir_Kind_Wait_Statement => 1320,
+      Iir_Kind_Variable_Assignment_Statement => 1326,
+      Iir_Kind_Return_Statement => 1332,
+      Iir_Kind_For_Loop_Statement => 1340,
+      Iir_Kind_While_Loop_Statement => 1347,
+      Iir_Kind_Next_Statement => 1353,
+      Iir_Kind_Exit_Statement => 1359,
+      Iir_Kind_Case_Statement => 1366,
+      Iir_Kind_Procedure_Call_Statement => 1371,
+      Iir_Kind_If_Statement => 1379,
+      Iir_Kind_Elsif => 1384,
+      Iir_Kind_Character_Literal => 1391,
+      Iir_Kind_Simple_Name => 1398,
+      Iir_Kind_Selected_Name => 1406,
+      Iir_Kind_Operator_Symbol => 1411,
+      Iir_Kind_Selected_By_All_Name => 1416,
+      Iir_Kind_Parenthesis_Name => 1420,
+      Iir_Kind_External_Constant_Name => 1429,
+      Iir_Kind_External_Signal_Name => 1438,
+      Iir_Kind_External_Variable_Name => 1447,
+      Iir_Kind_Package_Pathname => 1450,
+      Iir_Kind_Absolute_Pathname => 1451,
+      Iir_Kind_Relative_Pathname => 1452,
+      Iir_Kind_Pathname_Element => 1456,
+      Iir_Kind_Base_Attribute => 1458,
+      Iir_Kind_Left_Type_Attribute => 1463,
+      Iir_Kind_Right_Type_Attribute => 1468,
+      Iir_Kind_High_Type_Attribute => 1473,
+      Iir_Kind_Low_Type_Attribute => 1478,
+      Iir_Kind_Ascending_Type_Attribute => 1483,
+      Iir_Kind_Image_Attribute => 1489,
+      Iir_Kind_Value_Attribute => 1495,
+      Iir_Kind_Pos_Attribute => 1501,
+      Iir_Kind_Val_Attribute => 1507,
+      Iir_Kind_Succ_Attribute => 1513,
+      Iir_Kind_Pred_Attribute => 1519,
+      Iir_Kind_Leftof_Attribute => 1525,
+      Iir_Kind_Rightof_Attribute => 1531,
+      Iir_Kind_Delayed_Attribute => 1539,
+      Iir_Kind_Stable_Attribute => 1547,
+      Iir_Kind_Quiet_Attribute => 1555,
+      Iir_Kind_Transaction_Attribute => 1563,
+      Iir_Kind_Event_Attribute => 1567,
+      Iir_Kind_Active_Attribute => 1571,
+      Iir_Kind_Last_Event_Attribute => 1575,
+      Iir_Kind_Last_Active_Attribute => 1579,
+      Iir_Kind_Last_Value_Attribute => 1583,
+      Iir_Kind_Driving_Attribute => 1587,
+      Iir_Kind_Driving_Value_Attribute => 1591,
+      Iir_Kind_Behavior_Attribute => 1591,
+      Iir_Kind_Structure_Attribute => 1591,
+      Iir_Kind_Simple_Name_Attribute => 1598,
+      Iir_Kind_Instance_Name_Attribute => 1603,
+      Iir_Kind_Path_Name_Attribute => 1608,
+      Iir_Kind_Left_Array_Attribute => 1615,
+      Iir_Kind_Right_Array_Attribute => 1622,
+      Iir_Kind_High_Array_Attribute => 1629,
+      Iir_Kind_Low_Array_Attribute => 1636,
+      Iir_Kind_Length_Array_Attribute => 1643,
+      Iir_Kind_Ascending_Array_Attribute => 1650,
+      Iir_Kind_Range_Array_Attribute => 1657,
+      Iir_Kind_Reverse_Range_Array_Attribute => 1664,
+      Iir_Kind_Attribute_Name => 1672
      );
 
    function Get_Fields (K : Iir_Kind) return Fields_Array
@@ -4300,8 +4293,6 @@ package body Nodes_Meta is
             return Get_Elab_Flag (N);
          when Field_Index_Constraint_Flag =>
             return Get_Index_Constraint_Flag (N);
-         when Field_Has_Implicit_Conversion =>
-            return Get_Has_Implicit_Conversion (N);
          when Field_Aggr_Dynamic_Flag =>
             return Get_Aggr_Dynamic_Flag (N);
          when Field_Aggr_Others_Flag =>
@@ -4408,8 +4399,6 @@ package body Nodes_Meta is
             Set_Elab_Flag (N, V);
          when Field_Index_Constraint_Flag =>
             Set_Index_Constraint_Flag (N, V);
-         when Field_Has_Implicit_Conversion =>
-            Set_Has_Implicit_Conversion (N, V);
          when Field_Aggr_Dynamic_Flag =>
             Set_Aggr_Dynamic_Flag (N, V);
          when Field_Aggr_Others_Flag =>
@@ -6930,7 +6919,6 @@ 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
@@ -8653,11 +8641,6 @@ package body Nodes_Meta is
       end case;
    end Has_Expr_Staticness;
 
-   function Has_Has_Implicit_Conversion (K : Iir_Kind) return Boolean is
-   begin
-      return K = Iir_Kind_Function_Call;
-   end Has_Has_Implicit_Conversion;
-
    function Has_Error_Origin (K : Iir_Kind) return Boolean is
    begin
       return K = Iir_Kind_Error;
diff --git a/src/vhdl/nodes_meta.ads b/src/vhdl/nodes_meta.ads
index 5c740b5fc..ce1d33c55 100644
--- a/src/vhdl/nodes_meta.ads
+++ b/src/vhdl/nodes_meta.ads
@@ -278,7 +278,6 @@ package Nodes_Meta is
       Field_Named_Entity,
       Field_Alias_Declaration,
       Field_Expr_Staticness,
-      Field_Has_Implicit_Conversion,
       Field_Error_Origin,
       Field_Operand,
       Field_Left,
@@ -762,7 +761,6 @@ package Nodes_Meta is
    function Has_Named_Entity (K : Iir_Kind) return Boolean;
    function Has_Alias_Declaration (K : Iir_Kind) return Boolean;
    function Has_Expr_Staticness (K : Iir_Kind) return Boolean;
-   function Has_Has_Implicit_Conversion (K : Iir_Kind) return Boolean;
    function Has_Error_Origin (K : Iir_Kind) return Boolean;
    function Has_Operand (K : Iir_Kind) return Boolean;
    function Has_Left (K : Iir_Kind) return Boolean;
diff --git a/src/vhdl/sem_expr.adb b/src/vhdl/sem_expr.adb
index bbc9aaa22..8a7239a0f 100644
--- a/src/vhdl/sem_expr.adb
+++ b/src/vhdl/sem_expr.adb
@@ -1587,11 +1587,7 @@ package body Sem_Expr is
    --
    --  If there are two functions, one primitive of a universal
    --  type and the other not, return the primitive of the universal type.
-   --  This rule is *not* from LRM (but from Ada) and allows to resolve
-   --  common cases such as:
-   --    constant c1 : integer := - 4; -- or '+', 'abs'
-   --    constant c2 : integer := 2 ** 3;
-   --    constant c3 : integer := 3 - 2; -- or '+', '*', '/'...
+   --  This implements implicit type conversions rules.
    function Get_Non_Implicit_Subprogram (List : Iir_List) return Iir
    is
       El : Iir;
diff --git a/src/vhdl/sem_names.adb b/src/vhdl/sem_names.adb
index 478499da5..5f3854a96 100644
--- a/src/vhdl/sem_names.adb
+++ b/src/vhdl/sem_names.adb
@@ -187,13 +187,25 @@ package body Sem_Names is
       List : constant Iir_List := Get_Overload_List (Res);
       Call : Iir;
       El : Iir;
+      Imp : Iir;
+      Inter : Iir;
    begin
       Call := Null_Iir;
       for I in Natural loop
          El := Get_Nth_Element (List, I);
          exit when El = Null_Iir;
          if Get_Kind (El) = Iir_Kind_Function_Call then
-            if not Get_Has_Implicit_Conversion (El) then
+            Imp := Get_Implementation (El);
+            Inter := Get_Interface_Declaration_Chain (Imp);
+            if Get_Type (Inter) = Universal_Integer_Type_Definition
+              or else Get_Type (Inter) = Universal_Real_Type_Definition
+            then
+               --  The type of the first interface is a universal type.  So,
+               --  there were no implicit conversions.  Once there is an
+               --  implicit conversion, the only way to 'convert' to a
+               --  universal type is through T'Pos, which has to be resolved.
+               --  Note: there are no interface of convertible types.
+               --  GHDL: this is not proven...
                if Call /= Null_Iir then
                   --  More than one call without implicit conversion.
                   return Null_Iir;
@@ -2285,7 +2297,6 @@ package body Sem_Names is
             if Match /= Not_Compatible then
                Call := Sem_As_Function_Call
                  (Prefix_Name, Sub_Name, Assoc_Chain);
-               Set_Has_Implicit_Conversion (Call, Match = Via_Conversion);
                Add_Result (Res, Call);
                Used := True;
             end if;