lib-load.ads, [...] (Load_Unit): Addition of a new parameter that indicates if...

2005-06-14  Javier Miranda  <miranda@adacore.com>
	    Jose Ruiz  <ruiz@adacore.com>
	    Robert Dewar  <dewar@adacore.com>
	    Ed Schonberg  <schonberg@adacore.com>

	* lib-load.ads, lib-load.adb (Load_Unit): Addition of a new parameter
	that indicates if we are parsing a compilation unit found in a
	limited-with clause.
	It is use to avoid the circularity check.

	* par.ads, par.adb (Par): Addition of a new parameter to indicate if
	we are parsing a compilation unit found in a limited-with clause. This
	is use to avoid the circularity check.

	* par-load.adb (Load): Indicate Lib.Load_Unit if we are loading the
	unit as a consequence of parsing a limited-with clause. This is used
	to avoid the circularity check.

	* sem_ch10.adb: Suppress Ada 2005 unit warning if -gnatwY used
	(Analyze_Context): Limited-with clauses are now allowed
	in more compilation units.
	(Analyze_Subunit_Context, Check_Parent): Protect the frontend
	againts previously reported critical errors in context clauses
	(Install_Limited_Withed_Unit): Code cleanup plus static detection
	of two further errors: renamed subprograms and renamed packages
	are not allowed in limited with clauses.
	(Install_Siblings): Do not install private_with_clauses on the package
	declaration for a non-private child unit.
	(Re_Install_Parents): When a parent of the subunit is reinstalled,
	reset visibility of child units properly.
	(Install_Withed_Unit): When a child unit appears in a with_clause of its
	parent, it is immediately visible.

From-SVN: r101045

1 files changed, 27 insertions, 10 deletions

diff --git a/gcc/ada/lib-load.adb b/gcc/ada/lib-load.adb
index 59879f0..16d610a 100644
--- a/gcc/ada/lib-load.adb
+++ b/gcc/ada/lib-load.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2004 Free Software Foundation, Inc.          --
+--          Copyright (C) 1992-2005 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- --
@@ -38,6 +38,7 @@ with Osint;    use Osint;
 with Osint.C;  use Osint.C;
 with Output;   use Output;
 with Par;
+with Restrict; use Restrict;
 with Scn;      use Scn;
 with Sinfo;    use Sinfo;
 with Sinput;   use Sinput;
@@ -236,12 +237,13 @@ package body Lib.Load is
    ---------------
 
    function Load_Unit
-     (Load_Name  : Unit_Name_Type;
-      Required   : Boolean;
-      Error_Node : Node_Id;
-      Subunit    : Boolean;
-      Corr_Body  : Unit_Number_Type := No_Unit;
-      Renamings  : Boolean          := False) return Unit_Number_Type
+     (Load_Name         : Unit_Name_Type;
+      Required          : Boolean;
+      Error_Node        : Node_Id;
+      Subunit           : Boolean;
+      Corr_Body         : Unit_Number_Type := No_Unit;
+      Renamings         : Boolean          := False;
+      From_Limited_With : Boolean          := False) return Unit_Number_Type
    is
       Calling_Unit : Unit_Number_Type;
       Uname_Actual : Unit_Name_Type;
@@ -487,7 +489,7 @@ package body Lib.Load is
                        or else Acts_As_Spec (Units.Table (Unum).Cunit))
            and then (Nkind (Error_Node) /= N_With_Clause
                        or else not Limited_Present (Error_Node))
-
+           and then not From_Limited_With
          then
             if Debug_Flag_L then
                Write_Str ("  circular dependency encountered");
@@ -561,7 +563,8 @@ package body Lib.Load is
                Multiple_Unit_Index := Get_Unit_Index (Uname_Actual);
                Units.Table (Unum).Munit_Index := Multiple_Unit_Index;
                Initialize_Scanner (Unum, Source_Index (Unum));
-               Discard_List (Par (Configuration_Pragmas => False));
+               Discard_List (Par (Configuration_Pragmas => False,
+                                  From_Limited_With     => From_Limited_With));
                Multiple_Unit_Index := Save_Index;
                Set_Loading (Unum, False);
             end;
@@ -606,8 +609,22 @@ package body Lib.Load is
             --  Generate message if unit required
 
             if Required and then Present (Error_Node) then
-
                if Is_Predefined_File_Name (Fname) then
+
+                  --  This is a predefined library unit which is not present
+                  --  in the run time. If a predefined unit is not available
+                  --  it may very likely be the case that there is also pragma
+                  --  Restriction forbidding its usage. This is typically the
+                  --  case when building a configurable run time, where the
+                  --  usage of certain run-time units units is restricted by
+                  --  means of both the corresponding pragma Restriction (such
+                  --  as No_Calendar), and by not including the unit. Hence,
+                  --  we check whether this predefined unit is forbidden, so
+                  --  that the message about the restriction violation is
+                  --  generated, if needed.
+
+                  Check_Restricted_Unit (Load_Name, Error_Node);
+
                   Error_Msg_Name_1 := Uname_Actual;
                   Error_Msg
                     ("% is not a predefined library unit", Load_Msg_Sloc);