gnat_ugn.texi: Document -gnateu switch.

2013-10-14  Robert Dewar  <dewar@adacore.com>

	* gnat_ugn.texi: Document -gnateu switch.
	* opt.ads (Ignore_Unrecognized_VWY_Switches): New switch.
	* stylesw.adb: Ignore unrecognized switch if
	Ignore_Unrecognized_VWY_Switches set.
	* switch-c.adb: Implement -gnateu (sets
	Ignore_Unrecognized_VWY_Switches).
	* validsw.adb: Ignore unrecognized switch if
	Ignore_Unrecognized_VWY_Switches set.
	* warnsw.adb: Ignore unrecognized switch if
	Ignore_Unrecognized_VWY_Switches set.

From-SVN: r203536

7 files changed, 70 insertions, 12 deletions

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index ab038b7..16fe13c6 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,5 +1,18 @@
 2013-10-14  Robert Dewar  <dewar@adacore.com>
 
+	* gnat_ugn.texi: Document -gnateu switch.
+	* opt.ads (Ignore_Unrecognized_VWY_Switches): New switch.
+	* stylesw.adb: Ignore unrecognized switch if
+	Ignore_Unrecognized_VWY_Switches set.
+	* switch-c.adb: Implement -gnateu (sets
+	Ignore_Unrecognized_VWY_Switches).
+	* validsw.adb: Ignore unrecognized switch if
+	Ignore_Unrecognized_VWY_Switches set.
+	* warnsw.adb: Ignore unrecognized switch if
+	Ignore_Unrecognized_VWY_Switches set.
+
+2013-10-14  Robert Dewar  <dewar@adacore.com>
+
 	* exp_prag.adb, sem_prag.adb, a-exexda.adb, s-vmexta.ads: Minor
 	reformatting.
 
diff --git a/gcc/ada/gnat_ugn.texi b/gcc/ada/gnat_ugn.texi
index 7374f04..4078002 100644
--- a/gcc/ada/gnat_ugn.texi
+++ b/gcc/ada/gnat_ugn.texi
@@ -3829,6 +3829,14 @@ Synonym of @option{-fdump-scos}, kept for backards compatibility.
 @cindex @option{-gnatet} (@command{gcc})
 Generate target dependent information.
 
+@item -gnateu
+@cindex @option{-gnateu} (@command{gcc})
+Ignore unrecognized validity, warning, and style switches that
+apppear after this switch is given. This may be useful when
+compiling sources developed on a later version of the compiler
+with an earlier version. Of course the earlier version must
+support this switch.
+
 @item ^-gnateV^/PARAMETER_VALIDITY_CHECK^
 @cindex @option{-gnateV} (@command{gcc})
 Check validity of subprogram parameters.
diff --git a/gcc/ada/opt.ads b/gcc/ada/opt.ads
index 42b1369..492d5bc 100644
--- a/gcc/ada/opt.ads
+++ b/gcc/ada/opt.ads
@@ -719,6 +719,12 @@ package Opt is
    --  Set True to ignore all Style_Checks pragmas. Can be set True by use
    --  of -gnateY.
 
+   Ignore_Unrecognized_VWY_Switches : Boolean := False;
+   --  GNAT
+   --  Set True to ignore unrecognized y, V, w switches. Can be set True
+   --  by use of -gnateu, causing subsequent unrecognized switches to result
+   --  in a warning rather than an error.
+
    Implementation_Unit_Warnings : Boolean := True;
    --  GNAT
    --  Set True to active warnings for use of implementation internal units.
diff --git a/gcc/ada/stylesw.adb b/gcc/ada/stylesw.adb
index 7b78a16..a708da9 100644
--- a/gcc/ada/stylesw.adb
+++ b/gcc/ada/stylesw.adb
@@ -25,6 +25,7 @@
 
 with Hostparm; use Hostparm;
 with Opt;      use Opt;
+with Output;   use Output;
 
 package body Stylesw is
 
@@ -466,9 +467,13 @@ package body Stylesw is
                null;
 
             when others =>
-               Err_Col := Err_Col - 1;
-               Bad_Style_Switch ("invalid style switch: " & C);
-               return;
+               if Ignore_Unrecognized_VWY_Switches then
+                  Write_Line ("unrecognized switch -gnaty" & C & " ignored");
+               else
+                  Err_Col := Err_Col - 1;
+                  Bad_Style_Switch ("invalid style switch: " & C);
+                  return;
+               end if;
             end case;
 
          --  Turning switches off
@@ -571,9 +576,13 @@ package body Stylesw is
                null;
 
             when others =>
-               Err_Col := Err_Col - 1;
-               Bad_Style_Switch ("invalid style switch: " & C);
-               return;
+               if Ignore_Unrecognized_VWY_Switches then
+                  Write_Line ("unrecognized switch -gnaty-" & C & " ignored");
+               else
+                  Err_Col := Err_Col - 1;
+                  Bad_Style_Switch ("invalid style switch: " & C);
+                  return;
+               end if;
             end case;
          end if;
       end loop;
diff --git a/gcc/ada/switch-c.adb b/gcc/ada/switch-c.adb
index 197be06..0d80f44 100644
--- a/gcc/ada/switch-c.adb
+++ b/gcc/ada/switch-c.adb
@@ -717,6 +717,12 @@ package body Switch.C is
 
                      return;
 
+                  --  -gnateu (unrecognized y,V,w switches)
+
+                  when 'u' =>
+                     Ptr := Ptr + 1;
+                     Ignore_Unrecognized_VWY_Switches := True;
+
                   --  -gnateV (validity checks on parameters)
 
                   when 'V' =>
diff --git a/gcc/ada/validsw.adb b/gcc/ada/validsw.adb
index b37825e..517180a 100644
--- a/gcc/ada/validsw.adb
+++ b/gcc/ada/validsw.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 2001-2012, Free Software Foundation, Inc.         --
+--          Copyright (C) 2001-2013, 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- --
@@ -23,7 +23,8 @@
 --                                                                          --
 ------------------------------------------------------------------------------
 
-with Opt; use Opt;
+with Opt;    use Opt;
+with Output; use Output;
 
 package body Validsw is
 
@@ -229,9 +230,14 @@ package body Validsw is
                null;
 
             when others =>
-               OK      := False;
-               Err_Col := J - 1;
-               return;
+               if Ignore_Unrecognized_VWY_Switches then
+                  Write_Line ("unrecognized switch -gnatV" & C & " ignored");
+               else
+                  OK      := False;
+                  Err_Col := J - 1;
+                  return;
+               end if;
+
          end case;
       end loop;
 
diff --git a/gcc/ada/warnsw.adb b/gcc/ada/warnsw.adb
index 36360f9..a957138 100644
--- a/gcc/ada/warnsw.adb
+++ b/gcc/ada/warnsw.adb
@@ -25,6 +25,7 @@
 
 with Err_Vars; use Err_Vars;
 with Opt;      use Opt;
+with Output;   use Output;
 
 package body Warnsw is
 
@@ -386,7 +387,11 @@ package body Warnsw is
             No_Warn_On_Non_Local_Exception      := True;
 
          when others =>
-            return False;
+            if Ignore_Unrecognized_VWY_Switches then
+               Write_Line ("unrecognized switch -gnatw." & C & " ignored");
+            else
+               return False;
+            end if;
       end case;
 
       return True;
@@ -672,6 +677,11 @@ package body Warnsw is
             Warn_On_Unchecked_Conversion        := False;
 
          when others =>
+            if Ignore_Unrecognized_VWY_Switches then
+               Write_Line ("unrecognized switch -gnatw" & C & " ignored");
+            else
+               return False;
+            end if;
             return False;
       end case;