2010-01-26 Robert Dewar <dewar@adacore.com>

[pf3gnuchains/gcc-fork.git] / gcc / ada / back_end.adb

diff --git a/gcc/ada/back_end.adb b/gcc/ada/back_end.adb
index 7a4e4da..a15d9ec 100644 (file)
--- a/gcc/ada/back_end.adb
+++ b/gcc/ada/back_end.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2008, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2009, 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- --
@@ -158,12 +158,10 @@ package body Back_End is
       --  entire string should consist of valid switch characters, except that
       --  an optional terminating NUL character is allowed.
       --
-      --  Back end switches have already been checked and processed by GCC
-      --  in toplev.c, so no errors can occur and control will always return.
-      --  The switches must still be scanned to skip the arguments of the
-      --  "-o" or the (undocumented) "-dumpbase" switch, by incrementing
-      --  the Next_Arg variable. The "-dumpbase" switch is used to set the
-      --  basename for GCC dumpfiles.
+      --  Back end switches have already been checked and processed by GCC in
+      --  toplev.c, so no errors can occur and control will always return. The
+      --  switches must still be scanned to skip "-o" or internal GCC switches
+      --  with their argument.
 
       -------------
       -- Len_Arg --
@@ -186,21 +184,13 @@ package body Back_End is
 
       procedure Scan_Back_End_Switches (Switch_Chars : String) is
          First : constant Positive := Switch_Chars'First + 1;
-         Last  : Natural := Switch_Chars'Last;
+         Last  : constant Natural  := Switch_Last (Switch_Chars);
 
       begin
-         if Last >= First
-           and then Switch_Chars (Last) = ASCII.NUL
-         then
-            Last := Last - 1;
-         end if;
-
-         --  For switches -o, -dumpbase, --param, skip following argument and
-         --  do not store either the switch or the following argument.
+         --  Skip -o or internal GCC switches together with their argument
 
-         if Switch_Chars (First .. Last) = "o"        or else
-            Switch_Chars (First .. Last) = "dumpbase" or else
-            Switch_Chars (First .. Last) = "-param"
+         if Switch_Chars (First .. Last) = "o"
+           or else Is_Internal_GCC_Switch (Switch_Chars)
          then
             Next_Arg := Next_Arg + 1;
 
@@ -219,6 +209,13 @@ package body Back_End is
 
             if Switch_Chars (First .. Last) = "fno-inline" then
                Opt.Suppress_All_Inlining := True;
+
+            --  Another special check, the switch -fpreserve-control-flow
+            --  which is also a back end switch sets the front end flag
+            --  that inhibits improper control flow transformations.
+
+            elsif Switch_Chars (First .. Last) = "fpreserve-control-flow" then
+               Opt.Suppress_Control_Flow_Optimizations := True;
             end if;
          end if;
       end Scan_Back_End_Switches;