gnatbind.adb (Restriction_Could_Be_Set): New procedure

2008-04-08  Robert Dewar  <dewar@adacore.com>

	* gnatbind.adb (Restriction_Could_Be_Set): New procedure
	(List_Applicable_Restrictions): Do not list existing restrictions

From-SVN: r134035

gcc/ada/gnatbind.adb

@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2007, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2008, Free Software Foundation, Inc.         --
 --                                                                          --
 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
 -- terms of the  GNU General Public License as published  by the Free Soft- --
@@ -164,19 +164,68 @@ procedure Gnatbind is
       Additional_Restrictions_Listed : Boolean := False;
       --  Set True if we have listed header for restrictions
 
+      function Restriction_Could_Be_Set (R : Restriction_Id) return Boolean;
+      --  Returns True if the given restriction can be listed as an additional
+      --  restriction that could be set.
+
+      ------------------------------
+      -- Restriction_Could_Be_Set --
+      ------------------------------
+
+      function Restriction_Could_Be_Set (R : Restriction_Id) return Boolean is
+         CR : Restrictions_Info renames Cumulative_Restrictions;
+
       begin
-      --  Loop through restrictions
+         case R is
 
-      for R in All_Restrictions loop
-         if not No_Restriction_List (R) then
+            --  Boolean restriction
 
-            --  We list a restriction if it is not violated, or if
-            --  it is violated but the violation count is exactly known.
+            when All_Boolean_Restrictions =>
 
-            if Cumulative_Restrictions.Violated (R) = False
-              or else (R in All_Parameter_Restrictions
-                       and then
-                         Cumulative_Restrictions.Unknown (R) = False)
+               --  The condition for listing a boolean restriction as an
+               --  additional restriction that could be set is that it is
+               --  not violated by any unit, and not already set.
+
+               return CR.Violated (R) = False and then CR.Set (R) = False;
+
+            --  Parameter restriction
+
+            when All_Parameter_Restrictions =>
+
+               --  If the restriction is violated and the level of violation is
+               --  unknown, the restriction can definitely not be listed.
+
+               if CR.Violated (R) and then CR.Unknown (R) then
+                  return False;
+
+               --  We can list the restriction if it is not set
+
+               elsif not CR.Set (R) then
+                  return True;
+
+               --  We can list the restriction if is set to a greater value
+               --  than the maximum value known for the violation.
+
+               else
+                  return CR.Value (R) > CR.Count (R);
+               end if;
+
+            --  No other values for R possible
+
+            when others =>
+               raise Program_Error;
+
+         end case;
+      end Restriction_Could_Be_Set;
+
+   --  Start of processing for List_Applicable_Restrictions
+
+   begin
+      --  Loop through restrictions
+
+      for R in All_Restrictions loop
+         if not No_Restriction_List (R)
+            and then Restriction_Could_Be_Set (R)
          then
             if not Additional_Restrictions_Listed then
                Write_Eol;
@@ -206,7 +255,6 @@ procedure Gnatbind is
             Write_Str (");");
             Write_Eol;
          end if;
-         end if;
       end loop;
    end List_Applicable_Restrictions;