[Ada] Implement Rational profile to support non-standard renaming declarations

Arnaud Charlet charlet@adacore.com
Wed Feb 6 10:24:00 GMT 2013


We introduce the profile Rational and the corresponding pragma to support
legacy Rational code that accepts subprogram renaming declarations that are
not conformant to the RM.
The following program, compiled with -gnatc, must generate the message:

   ren.ads:12:51: subprogram cannot rename itself

The program must compile quietly if the pragma is uncommented.

---
--  pragma Rational;
package Ren is
   package P is
      type T is null record;
      function F (Obj : T) return integer;
   end P;

   use P;
   type DT is new T;
   package RR renames Ren;

   function F (New_Parameter : DT) return Integer renames RR.F;
end;

Tested on x86_64-pc-linux-gnu, committed on trunk

2013-02-06  Ed Schonberg  <schonberg@adacore.com>

	* snames.ads-tmpl: Add Name_Rational and pragma Rational.
	* par-prag.adb: Recognize pragma Rational.
	* opt.ads (Rational_Profile): flag to control compatibility mode
	with Rational compiler.
	* sem_ch8.adb (Analyze_Subprogram_Renaming): When Rational profile
	is enable, accept renaming declarations where the new subprogram
	and the renamed entity have the same name.
	* sem_prag.adb (analyze_pragma): Add pragma Rational, and recognize
	Rational as a profile.

-------------- next part --------------
Index: sem_prag.adb
===================================================================
--- sem_prag.adb	(revision 195788)
+++ sem_prag.adb	(working copy)
@@ -13859,7 +13859,7 @@
 
          --  pragma Profile (profile_IDENTIFIER);
 
-         --  profile_IDENTIFIER => Restricted | Ravenscar
+         --  profile_IDENTIFIER => Restricted | Ravenscar | Rational
 
          when Pragma_Profile =>
             Ada_2005_Pragma;
@@ -13879,6 +13879,9 @@
                     (Restricted,
                      N, Warn => Treat_Restrictions_As_Warnings);
 
+               elsif Chars (Argx) = Name_Rational then
+                  Rational_Profile := True;
+
                elsif Chars (Argx) = Name_No_Implementation_Extensions then
                   Set_Profile_Restrictions
                     (No_Implementation_Extensions,
@@ -14275,6 +14278,15 @@
             end if;
          end;
 
+         --------------
+         -- Rational --
+         --------------
+
+         --  pragma Rational, for compatibility with foreign compiler
+
+         when Pragma_Rational =>
+            Rational_Profile := True;
+
          -----------------------
          -- Relative_Deadline --
          -----------------------
@@ -16599,6 +16611,7 @@
       Pragma_Pure_12                        => -1,
       Pragma_Pure_Function                  => -1,
       Pragma_Queuing_Policy                 => -1,
+      Pragma_Rational                       => -1,
       Pragma_Ravenscar                      => -1,
       Pragma_Relative_Deadline              => -1,
       Pragma_Remote_Access_Type             => -1,
Index: par-prag.adb
===================================================================
--- par-prag.adb	(revision 195784)
+++ par-prag.adb	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2012, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2013, 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- --
@@ -1245,6 +1245,7 @@
            Pragma_Remote_Call_Interface          |
            Pragma_Remote_Types                   |
            Pragma_Restricted_Run_Time            |
+           Pragma_Rational                       |
            Pragma_Ravenscar                      |
            Pragma_Reviewable                     |
            Pragma_Share_Generic                  |
Index: sem_ch8.adb
===================================================================
--- sem_ch8.adb	(revision 195784)
+++ sem_ch8.adb	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2012, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2013, 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- --
@@ -2804,18 +2804,25 @@
             end if;
          end if;
 
-         if not Is_Actual
-           and then (Old_S = New_S
-                      or else
-                        (Nkind (Nam) /= N_Expanded_Name
-                          and then Chars (Old_S) = Chars (New_S))
-                      or else
-                        (Nkind (Nam) = N_Expanded_Name
-                          and then Entity (Prefix (Nam)) = Current_Scope
-                          and then
-                            Chars (Selector_Name (Nam)) = Chars (New_S)))
+         if Is_Actual then
+            null;
+
+         --  The following is illegal, because F hides whatever other F may
+         --  be around:
+         --     function F (..)  renames F;
+
+         elsif Old_S = New_S
+           or else (Nkind (Nam) /= N_Expanded_Name
+                     and then Chars (Old_S) = Chars (New_S))
          then
             Error_Msg_N ("subprogram cannot rename itself", N);
+
+         elsif Nkind (Nam) = N_Expanded_Name
+           and then Entity (Prefix (Nam)) = Current_Scope
+           and then Chars (Selector_Name (Nam)) = Chars (New_S)
+           and then not Rational_Profile
+         then
+            Error_Msg_N ("subprogram cannot rename itself", N);
          end if;
 
          Set_Convention (New_S, Convention (Old_S));
Index: opt.ads
===================================================================
--- opt.ads	(revision 195784)
+++ opt.ads	(working copy)
@@ -1181,6 +1181,10 @@
    --  Set to True if the tool should not have any output if there are no
    --  errors or warnings.
 
+   Rational_Profile : Boolean := False;
+   --  GNAT
+   --  Set to True to enable compatibility mode with Rational compiler.
+
    Replace_In_Comments : Boolean := False;
    --  GNATPREP
    --  Set to True if -C switch used
Index: snames.ads-tmpl
===================================================================
--- snames.ads-tmpl	(revision 195784)
+++ snames.ads-tmpl	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                             T e m p l a t e                              --
 --                                                                          --
---          Copyright (C) 1992-2012, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2013, 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- --
@@ -422,6 +422,7 @@
    Name_Profile_Warnings               : constant Name_Id := N + $; -- GNAT
    Name_Propagate_Exceptions           : constant Name_Id := N + $; -- GNAT
    Name_Queuing_Policy                 : constant Name_Id := N + $;
+   Name_Rational                       : constant Name_Id := N + $; -- GNAT
    Name_Ravenscar                      : constant Name_Id := N + $; -- GNAT
    Name_Restricted_Run_Time            : constant Name_Id := N + $; -- GNAT
    Name_Restrictions                   : constant Name_Id := N + $;
@@ -1717,6 +1718,7 @@
       Pragma_Profile_Warnings,
       Pragma_Propagate_Exceptions,
       Pragma_Queuing_Policy,
+      Pragma_Rational,
       Pragma_Ravenscar,
       Pragma_Restricted_Run_Time,
       Pragma_Restrictions,


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