[Ada] Replace chained if-then-elsif with case stmt for attribute ids

gcc/ada/

	* exp_spark.adb (Expand_SPARK_N_Attribute_Reference): Rewrite
	with a CASE statement.

diff --git a/gcc/ada/exp_spark.adb b/gcc/ada/exp_spark.adb
index 883a819ec7997b7f6da6af0ecffc2d3700c1410a..7909944f61b83e5c8d7463e4ee2c020ebc26427a 100644 (file)
--- a/gcc/ada/exp_spark.adb
+++ b/gcc/ada/exp_spark.adb
@@ -374,101 +374,105 @@ package body Exp_SPARK is
       Expr    : Node_Id;
 
    begin
-      if Attr_Id = Attribute_To_Address then
+      case Attr_Id is
+         when Attribute_To_Address =>
 
-         --  Extract and convert argument to expected type for call
+            --  Extract and convert argument to expected type for call
 
-         Expr :=
-           Make_Type_Conversion (Loc,
-             Subtype_Mark =>
-               New_Occurrence_Of (RTE (RE_Integer_Address), Loc),
-             Expression   => Relocate_Node (First (Expressions (N))));
+            Expr :=
+              Make_Type_Conversion (Loc,
+                Subtype_Mark =>
+                  New_Occurrence_Of (RTE (RE_Integer_Address), Loc),
+                Expression   => Relocate_Node (First (Expressions (N))));
 
-         --  Replace attribute reference with call
+            --  Replace attribute reference with call
 
-         Rewrite (N,
-           Make_Function_Call (Loc,
-             Name                   =>
-               New_Occurrence_Of (RTE (RE_To_Address), Loc),
-             Parameter_Associations => New_List (Expr)));
-         Analyze_And_Resolve (N, Typ);
-
-      elsif Attr_Id = Attribute_Object_Size
-        or else Attr_Id = Attribute_Size
-        or else Attr_Id = Attribute_Value_Size
-        or else Attr_Id = Attribute_VADS_Size
-      then
-         Exp_Attr.Expand_Size_Attribute (N);
-
-      --  For attributes which return Universal_Integer, introduce a conversion
-      --  to the expected type with the appropriate check flags set.
-
-      elsif Attr_Id = Attribute_Alignment
-        or else Attr_Id = Attribute_Bit
-        or else Attr_Id = Attribute_Bit_Position
-        or else Attr_Id = Attribute_Descriptor_Size
-        or else Attr_Id = Attribute_First_Bit
-        or else Attr_Id = Attribute_Last_Bit
-        or else Attr_Id = Attribute_Length
-        or else Attr_Id = Attribute_Max_Size_In_Storage_Elements
-        or else Attr_Id = Attribute_Pos
-        or else Attr_Id = Attribute_Position
-        or else Attr_Id = Attribute_Range_Length
-        or else Attr_Id = Attribute_Aft
-        or else Attr_Id = Attribute_Max_Alignment_For_Allocation
-      then
-         --  If the expected type is Long_Long_Integer, there will be no check
-         --  flag as the compiler assumes attributes always fit in this type.
-         --  Since in SPARK_Mode we do not take Storage_Error into account, we
-         --  cannot make this assumption and need to produce a check.
-         --  ??? It should be enough to add this check for attributes
-         --  'Length, 'Range_Length and 'Pos when the type is as big
-         --  as Long_Long_Integer.
-
-         declare
-            Typ : Entity_Id;
-         begin
-            if Attr_Id = Attribute_Range_Length
-              or else Attr_Id = Attribute_Pos
-            then
-               Typ := Etype (Prefix (N));
+            Rewrite
+              (N,
+               Make_Function_Call (Loc,
+                 Name                   =>
+                   New_Occurrence_Of (RTE (RE_To_Address), Loc),
+                 Parameter_Associations => New_List (Expr)));
+            Analyze_And_Resolve (N, Typ);
 
-            elsif Attr_Id = Attribute_Length then
-               Typ := Get_Index_Subtype (N);
+         when Attribute_Object_Size
+            | Attribute_Size
+            | Attribute_Value_Size
+            | Attribute_VADS_Size
+         =>
+            Exp_Attr.Expand_Size_Attribute (N);
+
+         --  For attributes which return Universal_Integer, introduce a
+         --  conversion to the expected type with the appropriate check flags
+         --  set.
+
+         when Attribute_Aft
+            | Attribute_Alignment
+            | Attribute_Bit
+            | Attribute_Bit_Position
+            | Attribute_Descriptor_Size
+            | Attribute_First_Bit
+            | Attribute_Last_Bit
+            | Attribute_Length
+            | Attribute_Max_Alignment_For_Allocation
+            | Attribute_Max_Size_In_Storage_Elements
+            | Attribute_Pos
+            | Attribute_Position
+            | Attribute_Range_Length
+         =>
+            --  If the expected type is Long_Long_Integer, there will be no
+            --  check flag as the compiler assumes attributes always fit in
+            --  this type. Since in SPARK_Mode we do not take Storage_Error
+            --  into account, we cannot make this assumption and need to
+            --  produce a check. ??? It should be enough to add this check for
+            --  attributes 'Length, 'Range_Length and 'Pos when the type is as
+            --  big as Long_Long_Integer.
+
+            declare
+               Typ : Entity_Id;
+            begin
+               if Attr_Id in Attribute_Pos | Attribute_Range_Length then
+                  Typ := Etype (Prefix (N));
+
+               elsif Attr_Id = Attribute_Length then
+                  Typ := Get_Index_Subtype (N);
+
+               else
+                  Typ := Empty;
+               end if;
 
-            else
-               Typ := Empty;
-            end if;
+               Apply_Universal_Integer_Attribute_Checks (N);
 
-            Apply_Universal_Integer_Attribute_Checks (N);
+               if Present (Typ)
+                 and then RM_Size (Typ) = RM_Size (Standard_Long_Long_Integer)
+               then
+                  --  ??? This should rather be a range check, but this would
+                  --  crash GNATprove which somehow recovers the proper kind
+                  --  of check anyway.
+                  Set_Do_Overflow_Check (N);
+               end if;
+            end;
 
-            if Present (Typ)
-              and then RM_Size (Typ) = RM_Size (Standard_Long_Long_Integer)
-            then
-               --  ??? This should rather be a range check, but this would
-               --  crash GNATprove which somehow recovers the proper kind
-               --  of check anyway.
-               Set_Do_Overflow_Check (N);
-            end if;
-         end;
+         when Attribute_Constrained =>
 
-      elsif Attr_Id = Attribute_Constrained then
+            --  If the prefix is an access to object, the attribute applies to
+            --  the designated object, so rewrite with an explicit dereference.
 
-         --  If the prefix is an access to object, the attribute applies to
-         --  the designated object, so rewrite with an explicit dereference.
+            if Is_Access_Type (Etype (Pref))
+              and then
+              (not Is_Entity_Name (Pref) or else Is_Object (Entity (Pref)))
+            then
+               Rewrite (Pref,
+                        Make_Explicit_Dereference (Loc, Relocate_Node (Pref)));
+               Analyze_And_Resolve (N, Standard_Boolean);
+            end if;
 
-         if Is_Access_Type (Etype (Pref))
-           and then
-             (not Is_Entity_Name (Pref) or else Is_Object (Entity (Pref)))
-         then
-            Rewrite (Pref,
-                     Make_Explicit_Dereference (Loc, Relocate_Node (Pref)));
-            Analyze_And_Resolve (N, Standard_Boolean);
-         end if;
+         when Attribute_Update =>
+            Expand_SPARK_Delta_Or_Update (Typ, First (Expressions (N)));
 
-      elsif Attr_Id = Attribute_Update then
-         Expand_SPARK_Delta_Or_Update (Typ, First (Expressions (N)));
-      end if;
+         when others =>
+            null;
+      end case;
    end Expand_SPARK_N_Attribute_Reference;
 
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