[Ada] enchance machinery which detects redundant qualifications

[Arnaud Charlet <charlet at adacore dot com>]

Tested on i686-linux, committed on trunk

This patch enchances the machinery which detects redundant qualifications
Source:
   procedure T is
      type New_Positive is new Positive;
      procedure Y (V : New_Positive) is begin null; end Y;
      P     : constant Positive := 1;
      New_P : constant New_Positive := 2;
   begin
      Y (New_Positive (New_P));
      for Loop_New_P in 1 .. New_P loop
         Y (Loop_New_P);
         Y (New_Positive (Loop_New_P));
         Y (New_Positive'(New_P));
         Y (New_Positive'(Loop_New_P));
      end loop;
   end T;
Compilation:
   gnatmake -gnatwr t.adb
Output:
   t.adb:7:10: warning: redundant conversion, "New_P" is of type "New_Positive"
   t.adb:10:13: warning: redundant conversion, "Loop_New_P" is of type "New_Positive"

2007-08-31  Hristian Kirtchev  <kirtchev@adacore.com>

        * restrict.adb, namet.adb, par-util.adb: Remove redundant type
	conversion.

	* sem_res.adb (Resolve_Qualified_Expression): Add machinery to detect
	simple redundant qualifications. The check is performed whenever the
	expression is a non-overloaded identifier.
	(Resolve_Type_Conversion): Enchance the redundant type conversion check
	to include loop parameters.
	(Valid_Conversion): Avoid generation of spurious error message.

Attachment: difs
Description: Text document