Add an UNSPEC_PROLOGUE_USE to prevent the link register from being considered dead.
[official-gcc.git] / gcc / ada / 4wexcpol.adb
blob7b9eee6a9fa5596fa9b9ac9acb6df87dcc0612f0
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- A D A . E X C E P T I O N S . P O L L --
6 -- (version supporting asynchronous abort test) --
7 -- --
8 -- B o d y --
9 -- --
10 -- --
11 -- Copyright (C) 1992-2000, Free Software Foundation, Inc. --
12 -- --
13 -- GNARL is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNARL; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
23 -- --
24 -- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
26 -- this unit does not by itself cause the resulting executable to be --
27 -- covered by the GNU General Public License. This exception does not --
28 -- however invalidate any other reasons why the executable file might be --
29 -- covered by the GNU Public License. --
30 -- --
31 -- GNARL was developed by the GNARL team at Florida State University. --
32 -- Extensive contributions were provided by Ada Core Technologies Inc. --
33 -- --
34 ------------------------------------------------------------------------------
36 -- This version is for targets that do not support per-thread asynchronous
37 -- signals. On such targets, we require compilation with the -gnatP switch
38 -- that activates periodic polling. Then in the body of the polling routine
39 -- we test for asynchronous abort.
41 -- NT, OS/2, HPUX/DCE and SCO currently use this file
43 with System.Soft_Links;
44 -- used for Check_Abort_Status
46 separate (Ada.Exceptions)
48 ----------
49 -- Poll --
50 ----------
52 procedure Poll is
53 begin
54 -- Test for asynchronous abort on each poll
56 if System.Soft_Links.Check_Abort_Status.all /= 0 then
57 raise Standard'Abort_Signal;
58 end if;
59 end Poll;