[Ada] Fix error detection of some renaming constructs

[Arnaud Charlet <charlet at adacore dot com>]

Tested on i686-linux, committed on HEAD

The following program must be rejected.

gcc -c -gnatws ren.adb

ren.adb:14:13: not mode conformant with declaration at line 4
ren.adb:14:13: mode of "C" does not match

procedure Ren is
    task type Tsk is
       entry E1;
       entry E2 (B : Boolean);
    end;

    BOOL : BOOLEAN := False;
    OBJ1 : TSK;
    OBJ2 : TSK;

    procedure RP1 renames OBJ1.E1;
     procedure RP2 (C : Boolean) renames OBJ2.E2;  --  OK
     procedure RP3 (C : out Boolean)               -- Error: C vs B modes
            renames OBJ2.E2;
    task body tsk is
    begin
       null;
     end;
begin
   null;
end;

Secondly, renaming an operator as a different operator is confusing, and is
often the indication of a typo. The following program:
--
package pack is
   type A_Type is tagged null record;
   function ">" (This, That : A_Type) return Boolean;
   function "<" (Left, Right : Pack.A_Type) return Boolean
      renames Pack.">";
end;
--
when compiled with -gnatc, now reports:
--
pack.ads:4:13: warning: ">" is being renamed as a different operator

2005-09-01  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch8.adb (Analyze_Renamed_Entry): For a renaming_as_declaration,
	verify that the procedure and the entry are mode conformant.
	(Analyze_Subprogram_Renaming): Emit a warning if an operator is renamed
	as a different operator, which is often a cut-and-paste error.

Attachment: difs.38
Description: Text document