2009-11-30 Thomas Quinot <quinot@adacore.com>

	* s-commun.adb, s-commun.ads: New internal support unit,
	allowing code sharing between GNAT.Sockets and
	GNAT.Serial_Communication.
	* g-sercom.ads, g-sercom-mingw.adb, g-sercom-linux.adb,
	g-socket.adb (GNAT.Sockets.Last_Index): Move to System.Communication.
	(GNAT.Serial_Communication.Read): Handle correctly the case where no
	data was read, and Buffer'First = Stream_Element_Offset'First.
	* Makefile.rtl: Add entry for s-commun
	* g-socthi-vms.adb, g-socthi-vms.ads, g-socthi-vxworks.adb,
	g-socthi-vxworks.ads, g-stseme.adb, g-socthi-mingw.ads,
	g-socthi.adb, g-socthi.ads (GNAT.Sockets.Thin.Socket_Error_Message):
	Reimplement in terms of System.CRTL.strerror.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@154758 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 64 insertions, 0 deletions

diff --git a/gcc/ada/g-stseme.adb b/gcc/ada/g-stseme.adb
new file mode 100644
index 00000000000..b09af1d6fb8
--- /dev/null
+++ b/gcc/ada/g-stseme.adb
@@ -0,0 +1,64 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--                  GNAT.SOCKETS.THIN.SOCKET_ERROR_MESSAGE                  --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--                     Copyright (C) 2007-2009, AdaCore                     --
+--                                                                          --
+-- 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- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This is the default implementation of this unit, using the standard C
+--  library's strerror(3) function. It is used on all platforms except Windows,
+--  since on that platform socket errno values are distinct from the system
+--  ones: there is a specific variant of this function in g-socthi-mingw.adb.
+
+with Ada.Unchecked_Conversion;
+with System.CRTL;
+
+separate (GNAT.Sockets.Thin)
+function Socket_Error_Message
+  (Errno : Integer) return C.Strings.chars_ptr
+is
+   use type Interfaces.C.Strings.chars_ptr;
+
+   pragma Warnings (Off);
+   function To_Chars_Ptr is
+     new Ada.Unchecked_Conversion
+       (System.Address, Interfaces.C.Strings.chars_ptr);
+   --  On VMS, the compiler warns because System.Address is 64 bits, but
+   --  chars_ptr is 32 bits. It should be safe, though, because strerror
+   --  will return a 32-bit pointer.
+   pragma Warnings (On);
+
+   C_Msg : C.Strings.chars_ptr;
+
+begin
+   C_Msg := To_Chars_Ptr (System.CRTL.strerror (Errno));
+   if C_Msg = C.Strings.Null_Ptr then
+      return Unknown_System_Error;
+   else
+      return C_Msg;
+   end if;
+end Socket_Error_Message;