gnat_rm.texi: Document s-ststop.ads

2009-07-15  Robert Dewar  <dewar@adacore.com>

	* gnat_rm.texi: Document s-ststop.ads

	* impunit.ad: (Map_Array): New table of alternative names
	(Get_Kind_Of_Unit): Return possible suggested alternative name

	* impunit.ads (Get_Kind_Of_Unit): Return possible suggested
	alternative name.

	* sem_ch10.adb (Analalyze_With_Clause): Add name of possible
	alternative unit if an implementation unit is with'ed.

From-SVN: r149685

gcc/ada/ChangeLog

 2009-07-15  Robert Dewar  <dewar@adacore.com>
 
+	* gnat_rm.texi: Document s-ststop.ads
+
+	* impunit.ad: (Map_Array): New table of alternative names
+	(Get_Kind_Of_Unit): Return possible suggested alternative name
+
+	* impunit.ads (Get_Kind_Of_Unit): Return possible suggested
+	alternative name.
+
+	* sem_ch10.adb (Analalyze_With_Clause): Add name of possible
+	alternative unit if an implementation unit is with'ed.
+
+2009-07-15  Robert Dewar  <dewar@adacore.com>
+
 	* gnat_ugn.texi: Minor updates.
 
 	* snames.ads-tmpl: Minor comment updates for Ada 2005 fully implemented

gcc/ada/gnat_rm.texi

@@ -409,6 +409,7 @@ The GNAT Library
 * System.Pool_Local (s-pooloc.ads)::
 * System.Restrictions (s-restri.ads)::
 * System.Rident (s-rident.ads)::
+* System.Strings.Stream_Ops (s-ststop.ads)::
 * System.Task_Info (s-tasinf.ads)::
 * System.Wch_Cnv (s-wchcnv.ads)::
 * System.Wch_Con (s-wchcon.ads)::
@@ -13597,6 +13598,7 @@ of GNAT, and will generate a warning message.
 * System.Pool_Local (s-pooloc.ads)::
 * System.Restrictions (s-restri.ads)::
 * System.Rident (s-rident.ads)::
+* System.Strings.Stream_Ops (s-ststop.ads)::
 * System.Task_Info (s-tasinf.ads)::
 * System.Wch_Cnv (s-wchcnv.ads)::
 * System.Wch_Con (s-wchcon.ads)::
@@ -14939,6 +14941,18 @@ It is not normally necessary to @code{with} this generic package
 since the necessary instantiation is included in
 package System.Restrictions.
 
+@node System.Strings.Stream_Ops (s-ststop.ads)
+@section @code{System.Strings.Stream_Ops} (@file{s-ststop.ads})
+@cindex @code{System.Strings.Stream_Ops} (@file{s-ststop.ads})
+@cindex Stream operations
+@cindex String stream operations
+
+@noindent
+This package provides a set of stream subprograms for standard string types.
+It is intended primarily to support implicit use of such subprograms when
+stream attributes are applied to string types, but the subprograms in this
+package can be used directly by application programs.
+
 @node System.Task_Info (s-tasinf.ads)
 @section @code{System.Task_Info} (@file{s-tasinf.ads})
 @cindex @code{System.Task_Info} (@file{s-tasinf.ads})

gcc/ada/impunit.adb

@@ -24,6 +24,7 @@
 ------------------------------------------------------------------------------
 
 with Atree;    use Atree;
+with Errout;   use Errout;
 with Sinfo;    use Sinfo;
 with Fname.UF; use Fname.UF;
 with Lib;      use Lib;
@@ -471,6 +472,42 @@ package body Impunit is
      "g-zspche",    -- GNAT.Wide_Wide_Spelling_Checker
      "g-zstspl");   -- GNAT.Wide_Wide_String_Split
 
+   -----------------------
+   -- Alternative Units --
+   -----------------------
+
+   --  For some implementation units, there is a unit in the GNAT library
+   --  that has identical functionality that is usable. If we have such a
+   --  case we record the appropriate Unit name in Error_Msg_String.
+
+   type Aunit_Record is record
+      Fname : String (1 .. 6);
+      Aname : String_Ptr;
+   end record;
+
+   --  Array of alternative unit names
+
+   Scasuti : aliased String := "GNAT.Case_Util";
+   Sos_lib : aliased String := "GNAT.OS_Lib";
+   Sregexp : aliased String := "GNAT.Regexp";
+   Sregpat : aliased String := "GNAT.Regpat";
+   Sstring : aliased String := "GNAT.Strings";
+   Sstusta : aliased String := "GNAT.Task_Stack_Usage";
+   Stasloc : aliased String := "GNAT.Task_Lock";
+   Sutf_32 : aliased String := "GNAT.UTF_32";
+
+   --  Array giving mapping
+
+   Map_Array : constant array (1 .. 8) of Aunit_Record := (
+                 ("casuti", Scasuti'Access),
+                 ("os_lib", Sos_lib'Access),
+                 ("regexp", Sregexp'Access),
+                 ("regpat", Sregpat'Access),
+                 ("string", Sstring'Access),
+                 ("stusta", Sstusta'Access),
+                 ("tasloc", Stasloc'Access),
+                 ("utf_32", Sutf_32'Access));
+
    ----------------------
    -- Get_Kind_Of_Unit --
    ----------------------
@@ -479,6 +516,8 @@ package body Impunit is
       Fname : constant File_Name_Type := Unit_File_Name (U);
 
    begin
+      Error_Msg_Strlen := 0;
+
       --  If length of file name is greater than 12, not predefined.
       --  The value 12 here is an 8 char name with extension .ads.
 
@@ -559,7 +598,23 @@ package body Impunit is
          return Ada_95_Unit;
       end if;
 
-      --  All tests failed, this is definitely an implementation unit
+      --  All tests failed, this is definitely an implementation unit. See if
+      --  we have an alternative name.
+
+      Get_Name_String (Fname);
+
+      if Name_Len = 12
+        and then Name_Buffer (1 .. 2) = "s-"
+        and then Name_Buffer (9 .. 12) = ".ads"
+      then
+         for J in Map_Array'Range loop
+            if Name_Buffer (3 .. 8) = Map_Array (J).Fname then
+               Error_Msg_Strlen := Map_Array (J).Aname'Length;
+               Error_Msg_String (1 .. Error_Msg_Strlen) :=
+                 Map_Array (J).Aname.all;
+            end if;
+         end loop;
+      end if;
 
       return Implementation_Unit;
    end Get_Kind_Of_Unit;

gcc/ada/impunit.ads

@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 2000-2007, Free Software Foundation, Inc.         --
+--          Copyright (C) 2000-2009, 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- --
@@ -55,7 +55,11 @@ package Impunit is
 
    function Get_Kind_Of_Unit (U : Unit_Number_Type) return Kind_Of_Unit;
    --  Given the unit number of a unit, this function determines the type
-   --  of the unit, as defined above.
+   --  of the unit, as defined above. If the result is Implementation_Unit,
+   --  then the name of a possible atlernative equivalent unit is placed in
+   --  Error_Msg_String/Slen on return. If there is no alternative name, or
+   --  if the result is not Implementation_Unit, then Error_Msg_Slen is zero
+   --  on return, indicating that no alternative name was found.
 
    function Is_Known_Unit (Nam : Node_Id) return Boolean;
    --  Nam is the possible name of a child unit, represented as a selected

gcc/ada/sem_ch10.adb

@@ -2334,12 +2334,10 @@ package body Sem_Ch10 is
          end if;
 
          --  Check for inappropriate with of internal implementation unit if we
-         --  are currently compiling the main unit and the main unit is itself
-         --  not an internal unit. We do not issue this message for implicit
-         --  with's generated by the compiler itself.
+         --  are not compiling an internal unit. We do not issue this message
+         --  for implicit with's generated by the compiler itself.
 
          if Implementation_Unit_Warnings
-           and then Current_Sem_Unit = Main_Unit
            and then not Intunit
            and then not Implicit_With (N)
          then
@@ -2350,10 +2348,17 @@ package body Sem_Ch10 is
             begin
                if U_Kind = Implementation_Unit then
                   Error_Msg_F ("& is an internal 'G'N'A'T unit?", Name (N));
-                  Error_Msg_F
-                    ("\use of this unit is non-portable " &
-                     "and version-dependent?",
-                     Name (N));
+
+                  --  Add alternative name if available, otherwise issue a
+                  --  general warning message.
+
+                  if Error_Msg_Strlen /= 0 then
+                     Error_Msg_F ("\use ""~"" instead", Name (N));
+                  else
+                     Error_Msg_F
+                       ("\use of this unit is non-portable " &
+                        "and version-dependent?", Name (N));
+                  end if;
 
                elsif U_Kind = Ada_05_Unit
                  and then Ada_Version < Ada_05