Patchwork Fix PR ada/52362

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Submitter Eric Botcazou
Date May 18, 2012, 9:05 p.m.
Message ID <201205182305.39231.ebotcazou@adacore.com>
Download mbox | patch
Permalink /patch/160154/
State New
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Comments

Eric Botcazou - May 18, 2012, 9:05 p.m.
Hi,

this is a regression present on mainline and 4.7 branch or, more precisely, if 
you use recent GNU linkers with LTO plugin.  During the link phase, gnatlink 
can decide to use a response file to pass a very long line to the linker.  It 
was actually using a linker script with the GNU linker, but this doesn't work 
in LTO mode if you use the plugin.

The fix is mainly in the Ada tools, but there is a hitch: when you pass a 
response file to the linker by means of the -Wl,@ option, it is intercepted by 
collect2.  And collect2 creates another response file for the linker proper 
only if HAVE_GNU_LD is set to 1.  Now HAVE_GNU_LD is set to 1 only if you pass 
the --with-ld= or --with-gnu-ld switches at configure time; in particular, for 
systems where the use of the GNU linker is the only choice and thus hardcoded 
in config.gcc (e.g. Linux), you can end up with HAVE_GNU_LD set to 0, breaking 
the response file mechanism.  Hence the configure.ac hunk.

Tested on i586-suse-linux and i686-pc-mingw32, OK for mainline and 4.7 branch?


2012-05-18  Eric Botcazou  <ebotcazou@adacore.com>

	PR ada/52362
	* config.gcc (i[34567]86-*-mingw* | x86_64-*-mingw*): Set gas and
	gnu_ld variables to yes.
	* configure.ac (HAVE_GNU_LD): Move to after config.gcc inclusion.
	(HAVE_GNU_AS): Likewise.
	* config.in: Regenerate.
	* configure: Likewise.
ada/
	* link.c (__gnat_object_file_option): Set to "-Wl,@" for GNU linker.
	(__gnat_using_gnu_linker): Delete.
	* gnatlink.adb (Gnatlink): Declare Object_File_Option_Ptr here...
	Declare Object_File_Option string constant and Using_GNU_response_file
	boolean constant.
	(Process_Binder_File): ...instead of here.  Delete Using_GNU_Linker,
	Opening and Closing local variables.  Do not handle the GNU linker
	specially.
	(Write_RF): New procedure to write into the response file.  Escape some
	characters if a GNU response file is used.  Keep track of error status.
	Invoke Write_RF to write into the response file.  Delete the file only
	if the link was successful.
	* mlib-utl.adb: Do not `with' package System.
	(Gcc): Likewise.  Declare Object_File_Option string constant and
	Using_GNU_response_file boolean constant.
	(Write_RF): Take a string instead of address and length.  Escape some
	characters if a GNU response file is used.
	Invoke Write_RF to write into the response file.  Delete the file only
	if the link was successful.  Do not warn if it cannot be deleted.


2012-05-18  Eric Botcazou  <ebotcazou@adacore.com>

	* gnat.dg/lto13.adb: New test.
Eric Botcazou - May 25, 2012, 7:08 a.m.
Paolo,

> The fix is mainly in the Ada tools, but there is a hitch: when you pass a
> response file to the linker by means of the -Wl,@ option, it is intercepted
> by collect2.  And collect2 creates another response file for the linker
> proper only if HAVE_GNU_LD is set to 1.  Now HAVE_GNU_LD is set to 1 only
> if you pass the --with-ld= or --with-gnu-ld switches at configure time; in
> particular, for systems where the use of the GNU linker is the only choice
> and thus hardcoded in config.gcc (e.g. Linux), you can end up with
> HAVE_GNU_LD set to 0, breaking the response file mechanism.  Hence the
> configure.ac hunk.
>
> Tested on i586-suse-linux and i686-pc-mingw32, OK for mainline and 4.7
> branch?
>
>
> 2012-05-18  Eric Botcazou  <ebotcazou@adacore.com>
>
> 	PR ada/52362
> 	* config.gcc (i[34567]86-*-mingw* | x86_64-*-mingw*): Set gas and
> 	gnu_ld variables to yes.
> 	* configure.ac (HAVE_GNU_LD): Move to after config.gcc inclusion.
> 	(HAVE_GNU_AS): Likewise.
> 	* config.in: Regenerate.
> 	* configure: Likewise.

What do you think about the above change?  Thanks in advance.
Paolo Bonzini - May 25, 2012, 7:23 a.m.
Il 18/05/2012 23:05, Eric Botcazou ha scritto:
> Hi,
> 
> this is a regression present on mainline and 4.7 branch or, more precisely, if 
> you use recent GNU linkers with LTO plugin.  During the link phase, gnatlink 
> can decide to use a response file to pass a very long line to the linker.  It 
> was actually using a linker script with the GNU linker, but this doesn't work 
> in LTO mode if you use the plugin.
> 
> The fix is mainly in the Ada tools, but there is a hitch: when you pass a 
> response file to the linker by means of the -Wl,@ option, it is intercepted by 
> collect2.  And collect2 creates another response file for the linker proper 
> only if HAVE_GNU_LD is set to 1.  Now HAVE_GNU_LD is set to 1 only if you pass 
> the --with-ld= or --with-gnu-ld switches at configure time; in particular, for 
> systems where the use of the GNU linker is the only choice and thus hardcoded 
> in config.gcc (e.g. Linux), you can end up with HAVE_GNU_LD set to 0, breaking 
> the response file mechanism.  Hence the configure.ac hunk.
> 
> Tested on i586-suse-linux and i686-pc-mingw32, OK for mainline and 4.7 branch?

Ok, thanks!

Paolo
Diego Novillo - June 5, 2012, 4:49 p.m.
On Fri, May 18, 2012 at 5:05 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:

>        * configure.ac (HAVE_GNU_LD): Move to after config.gcc inclusion.
>        (HAVE_GNU_AS): Likewise.
>        * config.in: Regenerate.
>        * configure: Likewise.

Eric,

This change is breaking bootstraps in one of the google branches
because it does not allow us to control the presence of GNU as with
the --with-gnu-as= configure flag.

When doing native bootstraps, we need to set --with-gnu-as=no because
binutils 'as' does not handle a flag that we pass to our own version
of 'as'.

This is a combination of problems, actually:

1- The local patch we have that enables the new flag is keyed on
HAVE_GNU_AS.  Easwaran, I think this is a patch of yours from Apr
2011:

2011-04-20  Easwaran Raman  <eraman@google.com>

        * gcc.c (asm_options): Pass --save-temps to assembler.

The change should not assume that HAVE_GNU_AS means that we can use
--save-temps.  You should use a new configuration flag for it.


2- Eric, your patch essentially disables the --with-gnu-as= flag.
When doing a native bootstrap on the 4.7 branch, HAVE_GNU_AS is set to
1, regardless of the value of --with-gnu-as.  The problem is that your
new test to decide whether to use gas just uses the value set in
config.gcc.

Easwaran, I will revert Eric's patch from our 4.7 branch.

Eric, shouldn't the whole section testing for GNU as move after the
inclusion of config.gcc?


Thanks.  Diego.
Eric Botcazou - June 6, 2012, 7:32 a.m.
> When doing native bootstraps, we need to set --with-gnu-as=no because
> binutils 'as' does not handle a flag that we pass to our own version
> of 'as'.

That looks like a kludge to me.  You can probably achieve the same effect with 
a script filtering out the unsupported flag.

> 2- Eric, your patch essentially disables the --with-gnu-as= flag.
> When doing a native bootstrap on the 4.7 branch, HAVE_GNU_AS is set to
> 1, regardless of the value of --with-gnu-as.  The problem is that your
> new test to decide whether to use gas just uses the value set in
> config.gcc.

But that's correct: the final say over --with-gnu-as is in config.gcc.  Without 
my patch, you have a disagreement between auto-host.h and config.gcc (hence 
tm.h ultimately) if the latter overrides -with-gnu-as, which can potentially 
lead to inconsistencies like in the linker case.

> Eric, shouldn't the whole section testing for GNU as move after the
> inclusion of config.gcc?

I don't think so, that would change the semantics of --with-gnu-as.
Diego Novillo - June 6, 2012, 11:11 a.m.
On 12-06-06 03:32 , Eric Botcazou wrote:
>> When doing native bootstraps, we need to set --with-gnu-as=no because
>> binutils 'as' does not handle a flag that we pass to our own version
>> of 'as'.
>
> That looks like a kludge to me.  You can probably achieve the same effect with
> a script filtering out the unsupported flag.

Agreed.  That bug that needs to be fixed in the branch.

> But that's correct: the final say over --with-gnu-as is in config.gcc.  Without
> my patch, you have a disagreement between auto-host.h and config.gcc (hence
> tm.h ultimately) if the latter overrides -with-gnu-as, which can potentially
> lead to inconsistencies like in the linker case.

So, why do we have the --with-gnu-as flag then?

>> Eric, shouldn't the whole section testing for GNU as move after the
>> inclusion of config.gcc?
>
> I don't think so, that would change the semantics of --with-gnu-as.

That's my point.  After your patch, --with-gnu-as has no meaning.  The 
user has no way of overriding the value guessed by config.gcc.


Diego.
Eric Botcazou - June 6, 2012, 11:23 a.m.
> So, why do we have the --with-gnu-as flag then?

Because, on some platforms like Solaris, you can use the system assembler or 
the GNU assembler, so nothing is hardcoded in config.gcc and --with-gnu-as 
makes it possible to pick one.  On Linux, it's always the GNU assembler so 
this is hardcoded.

> That's my point.  After your patch, --with-gnu-as has no meaning.  The
> user has no way of overriding the value guessed by config.gcc.

But that value isn't guessed at all: if it's set, then it's always correct.
Note that my patch didn't change that, i.e. the compiler was and is still 
configured for the GNU assembler whatever --with-gnu-as you pass on Linux.
Diego Novillo - June 6, 2012, 11:59 a.m.
On 12-06-06 07:23 , Eric Botcazou wrote:
>> So, why do we have the --with-gnu-as flag then?
>
> Because, on some platforms like Solaris, you can use the system assembler or
> the GNU assembler, so nothing is hardcoded in config.gcc and --with-gnu-as
> makes it possible to pick one.  On Linux, it's always the GNU assembler so
> this is hardcoded.

Ah, OK.

>> That's my point.  After your patch, --with-gnu-as has no meaning.  The
>> user has no way of overriding the value guessed by config.gcc.
>
> But that value isn't guessed at all: if it's set, then it's always correct.
> Note that my patch didn't change that, i.e. the compiler was and is still
> configured for the GNU assembler whatever --with-gnu-as you pass on Linux.

Actually, no.  If I undo your patch, I can control the value of 
HAVE_GNU_AS with the flag.  But you are right in that this makes no 
material difference in what we end up using.


Thanks.  Diego.

Patch

Index: config.gcc
===================================================================
--- config.gcc	(revision 187660)
+++ config.gcc	(working copy)
@@ -1470,6 +1470,8 @@ 
 	extra_objs="winnt.o winnt-stubs.o"
 	c_target_objs="${c_target_objs} msformat-c.o"
 	cxx_target_objs="${cxx_target_objs} winnt-cxx.o msformat-c.o"
+	gas=yes
+	gnu_ld=yes
 	default_use_cxa_atexit=yes
 	use_gcc_stdint=wrap
 	case ${enable_threads} in
Index: configure.ac
===================================================================
--- configure.ac	(revision 187660)
+++ configure.ac	(working copy)
@@ -213,9 +213,6 @@ 
 	[Define to enable the use of a default linker.])
 fi
 
-gnu_ld=`if test x"$gnu_ld_flag" = x"yes"; then echo 1; else echo 0; fi`
-AC_DEFINE_UNQUOTED(HAVE_GNU_LD, $gnu_ld, [Define if using GNU ld.])
-
 AC_MSG_CHECKING([whether a default linker was specified])
 if test x"${DEFAULT_LINKER+set}" = x"set"; then
   if test x"$gnu_ld_flag" = x"no"; then
@@ -256,9 +253,6 @@ 
 	[Define to enable the use of a default assembler.])
 fi
 
-gnu_as=`if test x"$gas_flag" = x"yes"; then echo 1; else echo 0; fi`
-AC_DEFINE_UNQUOTED(HAVE_GNU_AS, $gnu_as, [Define if using GNU as.])
-
 AC_MSG_CHECKING([whether a default assembler was specified])
 if test x"${DEFAULT_ASSEMBLER+set}" = x"set"; then
   if test x"$gas_flag" = x"no"; then
@@ -1328,6 +1322,12 @@ 
 efficiently supported by the host hardware.])
 fi
 
+gnu_ld_bool=`if test x"$gnu_ld" = x"yes"; then echo 1; else echo 0; fi`
+AC_DEFINE_UNQUOTED(HAVE_GNU_LD, $gnu_ld_bool, [Define to 1 if using GNU ld.])
+
+gnu_as_bool=`if test x"$gas" = x"yes"; then echo 1; else echo 0; fi`
+AC_DEFINE_UNQUOTED(HAVE_GNU_AS, $gnu_as_bool, [Define to 1 if using GNU as.])
+
 count=a
 for f in $host_xm_file; do
 	count=${count}x
Index: ada/mlib-utl.adb
===================================================================
--- ada/mlib-utl.adb	(revision 187660)
+++ ada/mlib-utl.adb	(working copy)
@@ -6,7 +6,7 @@ 
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---                     Copyright (C) 2002-2011, AdaCore                     --
+--                     Copyright (C) 2002-2012, 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- --
@@ -31,8 +31,6 @@ 
 
 with Interfaces.C.Strings; use Interfaces.C.Strings;
 
-with System;
-
 package body MLib.Utl is
 
    Adalib_Path : String_Access := null;
@@ -353,16 +351,13 @@ 
       --  Pointer to a string representing the linker option which specifies
       --  the response file.
 
-      Using_GNU_Linker : Boolean;
-      for Using_GNU_Linker'Size use Character'Size;
-      pragma Import (C, Using_GNU_Linker, "__gnat_using_gnu_linker");
-      --  Predicate indicating whether this target uses the GNU linker. In
-      --  this case we must output a GNU linker compatible response file.
+      Object_File_Option : constant String := Value (Object_File_Option_Ptr);
+      --  The linker option which specifies the response file as a string
 
-      Opening : aliased constant String := """";
-      Closing : aliased constant String := '"' & ASCII.LF;
-      --  Needed to quote object paths in object list files when GNU linker
-      --  is used.
+      Using_GNU_response_file : constant Boolean :=
+        Object_File_Option'Length > 0
+          and then Object_File_Option (Object_File_Option'Last) = '@';
+      --  Whether a GNU response file is used
 
       Tname    : String_Access;
       Tname_FD : File_Descriptor := Invalid_FD;
@@ -390,7 +385,7 @@ 
 
       Position : Object_Position;
 
-      procedure Write_RF (A : System.Address; N : Integer);
+      procedure Write_RF (S : String);
       --  Write a string to the response file and check if it was successful.
       --  Fail the program if it was not successful (disk full).
 
@@ -398,12 +393,38 @@ 
       -- Write_RF --
       --------------
 
-      procedure Write_RF (A : System.Address; N : Integer) is
-         Status : Integer;
+      procedure Write_RF (S : String) is
+         Success : Boolean := True;
       begin
-         Status := Write (Tname_FD, A, N);
+         --  If a GNU response file is used, space and backslash need to be
+         --  escaped because they are interpreted as a string separator and
+         --  an escape character respectively by the underlying mechanism.
+         --  On the other hand, quote and double-quote are not escaped since
+         --  they are interpreted as string delimiters on both sides.
 
-         if Status /= N then
+         if Using_GNU_response_file then
+            for I in S'Range loop
+               if S (I) = ' ' or else S (I) = '\' then
+                  if Write (Tname_FD, ASCII.BACK_SLASH'Address, 1) /= 1 then
+                     Success := False;
+                  end if;
+               end if;
+
+               if Write (Tname_FD, S (I)'Address, 1) /= 1 then
+                  Success := False;
+               end if;
+            end loop;
+         else
+            if Write (Tname_FD, S'Address, S'Length) /= S'Length then
+               Success := False;
+            end if;
+         end if;
+
+         if Write (Tname_FD, ASCII.LF'Address, 1) /= 1 then
+            Success := False;
+         end if;
+
+         if not Success then
             Fail ("cannot generate response file to link library: disk full");
          end if;
       end Write_RF;
@@ -529,53 +550,10 @@ 
 
          Create_Temp_File (Tname_FD, Tname);
 
-         --  If target is using the GNU linker we must add a special header
-         --  and footer in the response file.
-
-         --  The syntax is : INPUT (object1.o object2.o ... )
-
-         --  Because the GNU linker does not like name with characters such
-         --  as '!', we must put the object paths between double quotes.
-
-         if Using_GNU_Linker then
-            declare
-               GNU_Header : aliased constant String := "INPUT (";
-
-            begin
-               Write_RF (GNU_Header'Address, GNU_Header'Length);
-            end;
-         end if;
-
          for J in Objects'Range loop
-            --  Opening quote for GNU linker
-
-            if Using_GNU_Linker then
-               Write_RF (Opening'Address, 1);
-            end if;
-
-            Write_RF (Objects (J).all'Address, Objects (J).all'Length);
-
-            --  Closing quote for GNU linker
-
-            if Using_GNU_Linker then
-               Write_RF (Closing'Address, 2);
-
-            else
-               Write_RF (ASCII.LF'Address, 1);
-            end if;
+            Write_RF (Objects (J).all);
          end loop;
 
-         --  Handle GNU linker response file footer
-
-         if Using_GNU_Linker then
-            declare
-               GNU_Footer : aliased constant String := ")";
-
-            begin
-               Write_RF (GNU_Footer'Address, GNU_Footer'Length);
-            end;
-         end if;
-
          Close (Tname_FD, Closing_Status);
 
          if not Closing_Status then
@@ -583,8 +561,7 @@ 
          end if;
 
          A := A + 1;
-         Arguments (A) :=
-           new String'(Value (Object_File_Option_Ptr) & Tname.all);
+         Arguments (A) := new String'(Object_File_Option & Tname.all);
 
       else
          A := A + Objects'Length;
@@ -596,17 +573,15 @@ 
 
       Spawn (Driver.all, Arguments (1 .. A), Success);
 
-      if Tname /= null then
-         Delete_File (Tname.all, Closing_Status);
+      if Success then
+         --  Delete the temporary file used in conjunction with linking
+         --  if one was created.
 
-         if not Closing_Status then
-            Write_Str ("warning: could not delete response file """);
-            Write_Str (Tname.all);
-            Write_Line (""" to link library");
+         if Tname_FD /= Invalid_FD then
+            Delete_File (Tname.all);
          end if;
-      end if;
 
-      if not Success then
+      else
          if Driver_Name = No_Name then
             Fail (Gcc_Name.all & " execution error");
          else
Index: ada/gnatlink.adb
===================================================================
--- ada/gnatlink.adb	(revision 187660)
+++ ada/gnatlink.adb	(working copy)
@@ -178,6 +178,19 @@ 
    --  Predicate indicating whether the linker has an option whereby the
    --  names of object files can be passed to the linker in a file.
 
+   Object_File_Option_Ptr : Interfaces.C.Strings.chars_ptr;
+   pragma Import (C, Object_File_Option_Ptr, "__gnat_object_file_option");
+   --  Pointer to a string representing the linker option which specifies
+   --  the response file.
+
+   Object_File_Option : constant String := Value (Object_File_Option_Ptr);
+   --  The linker option which specifies the response file as a string
+
+   Using_GNU_response_file : constant Boolean :=
+     Object_File_Option'Length > 0
+       and then Object_File_Option (Object_File_Option'Last) = '@';
+   --  Whether a GNU response file is used
+
    Object_List_File_Required : Boolean := False;
    --  Set to True to force generation of a response file
 
@@ -760,28 +773,12 @@ 
       --  Pointer to string specifying the default extension for
       --  object libraries, e.g. Unix uses ".a", VMS uses ".olb".
 
-      Object_File_Option_Ptr : Interfaces.C.Strings.chars_ptr;
-      pragma Import (C, Object_File_Option_Ptr, "__gnat_object_file_option");
-      --  Pointer to a string representing the linker option which specifies
-      --  the response file.
-
-      Using_GNU_Linker : Boolean;
-      for Using_GNU_Linker'Size use Character'Size;
-      pragma Import (C, Using_GNU_Linker, "__gnat_using_gnu_linker");
-      --  Predicate indicating whether this target uses the GNU linker. In
-      --  this case we must output a GNU linker compatible response file.
-
       Separate_Run_Path_Options : Boolean;
       for Separate_Run_Path_Options'Size use Character'Size;
       pragma Import
         (C, Separate_Run_Path_Options, "__gnat_separate_run_path_options");
       --  Whether separate rpath options should be emitted for each directory
 
-      Opening : aliased constant String := """";
-      Closing : aliased constant String := '"' & ASCII.LF;
-      --  Needed to quote object paths in object list files when GNU linker
-      --  is used.
-
       procedure Get_Next_Line;
       --  Read the next line from the binder file without the line
       --  terminator.
@@ -804,6 +801,10 @@ 
       --  after Store_File_Context. The binder file context will be restored
       --  with the data stored by the last Store_File_Context call.
 
+      procedure Write_RF (S : String);
+      --  Write a string to the response file and check if it was successful.
+      --  Fail the program if it was not successful (disk full).
+
       -------------------
       -- Get_Next_Line --
       -------------------
@@ -897,6 +898,46 @@ 
          end if;
       end Store_File_Context;
 
+      --------------
+      -- Write_RF --
+      --------------
+
+      procedure Write_RF (S : String) is
+         Success : Boolean := True;
+      begin
+         --  If a GNU response file is used, space and backslash need to be
+         --  escaped because they are interpreted as a string separator and
+         --  an escape character respectively by the underlying mechanism.
+         --  On the other hand, quote and double-quote are not escaped since
+         --  they are interpreted as string delimiters on both sides.
+
+         if Using_GNU_response_file then
+            for I in S'Range loop
+               if S (I) = ' ' or else S (I) = '\' then
+                  if Write (Tname_FD, ASCII.BACK_SLASH'Address, 1) /= 1 then
+                     Success := False;
+                  end if;
+               end if;
+
+               if Write (Tname_FD, S (I)'Address, 1) /= 1 then
+                  Success := False;
+               end if;
+            end loop;
+         else
+            if Write (Tname_FD, S'Address, S'Length) /= S'Length then
+               Success := False;
+            end if;
+         end if;
+
+         if Write (Tname_FD, ASCII.LF'Address, 1) /= 1 then
+            Success := False;
+         end if;
+
+         if not Success then
+            Exit_With_Error ("Error generating response file: disk full");
+         end if;
+      end Write_RF;
+
    --  Start of processing for Process_Binder_File
 
    begin
@@ -985,61 +1026,14 @@ 
          --  ??? Status of Write and Close operations should be checked, and
          --  failure should occur if a status is wrong.
 
-         --  If target is using the GNU linker we must add a special header
-         --  and footer in the response file.
-
-         --  The syntax is : INPUT (object1.o object2.o ... )
-
-         --  Because the GNU linker does not like name with characters such
-         --  as '!', we must put the object paths between double quotes.
-
-         if Using_GNU_Linker then
-            declare
-               GNU_Header : aliased constant String := "INPUT (";
-
-            begin
-               Status := Write (Tname_FD, GNU_Header'Address,
-                 GNU_Header'Length);
-            end;
-         end if;
-
          for J in Objs_Begin .. Objs_End loop
+            Write_RF (Linker_Objects.Table (J).all);
 
-            --  Opening quote for GNU linker
-
-            if Using_GNU_Linker then
-               Status := Write (Tname_FD, Opening'Address, 1);
-            end if;
-
-            Status := Write (Tname_FD, Linker_Objects.Table (J).all'Address,
-                             Linker_Objects.Table (J).all'Length);
-
-            --  Closing quote for GNU linker
-
-            if Using_GNU_Linker then
-               Status := Write (Tname_FD, Closing'Address, 2);
-
-            else
-               Status := Write (Tname_FD, ASCII.LF'Address, 1);
-            end if;
-
             Response_File_Objects.Increment_Last;
             Response_File_Objects.Table (Response_File_Objects.Last) :=
               Linker_Objects.Table (J);
          end loop;
 
-         --  Handle GNU linker response file footer
-
-         if Using_GNU_Linker then
-            declare
-               GNU_Footer : aliased constant String := ")";
-
-            begin
-               Status := Write (Tname_FD, GNU_Footer'Address,
-                 GNU_Footer'Length);
-            end;
-         end if;
-
          Close (Tname_FD, Closing_Status);
 
          --  Add the special objects list file option together with the name
@@ -1047,7 +1041,7 @@ 
          --  file table.
 
          Linker_Objects.Table (Objs_Begin) :=
-           new String'(Value (Object_File_Option_Ptr) &
+           new String'(Object_File_Option &
                        Tname (Tname'First .. Tname'Last - 1));
 
          --  The slots containing these object file names are then removed
@@ -2213,14 +2207,15 @@ 
 
             System.OS_Lib.Spawn (Linker_Path.all, Args, Success);
 
-            --  Delete the temporary file used in conjunction with linking if
-            --  one was created. See Process_Bind_File for details.
+            if Success then
+               --  Delete the temporary file used in conjunction with linking
+               --  if one was created. See Process_Bind_File for details.
 
-            if Tname_FD /= Invalid_FD then
-               Delete (Tname);
-            end if;
+               if Tname_FD /= Invalid_FD then
+                  Delete (Tname);
+               end if;
 
-            if not Success then
+            else
                Error_Msg ("error when calling " & Linker_Path.all);
                Exit_Program (E_Fatal);
             end if;
Index: ada/link.c
===================================================================
--- ada/link.c	(revision 187660)
+++ ada/link.c	(working copy)
@@ -72,38 +72,22 @@ 
 /*  shared_libgcc_default gives the system dependent link method that       */
 /*  be used by default for linking libgcc (shared or static)                */
 
-/*  using_gnu_linker is set to 1 when the GNU linker is used under this     */
-/*  target.                                                                 */
-
 /*  separate_run_path_options is set to 1 when separate "rpath" arguments   */
 /*  must be passed to the linker for each directory in the rpath.           */
 
 /*  default_libgcc_subdir is the subdirectory name (from the installation   */
 /*  root) where we may find a shared libgcc to use by default.              */
 
-/*  RESPONSE FILE & GNU LINKER                                              */
-/*  --------------------------                                              */
-/*  objlist_file_supported and using_gnu_link used together tell gnatlink   */
-/*  to generate a GNU style response file. Note that object_file_option     */
-/*  must be set to "" in this case, since no option is required for a       */
-/*  response file to be passed to GNU ld. With a GNU linker we use the      */
-/*  linker script to implement the response file feature. Any file passed   */
-/*  in the GNU ld command line with an unknown extension is supposed to be  */
-/*  a linker script. Each linker script augment the current configuration.  */
-/*  The format of such response file is as follow :                         */
-/*  INPUT (obj1.p obj2.o ...)                                               */
-
 #define SHARED 'H'
 #define STATIC 'T'
 
 #if defined (__WIN32)
-const char *__gnat_object_file_option = "";
+const char *__gnat_object_file_option = "-Wl,@";
 const char *__gnat_run_path_option = "";
 int __gnat_link_max = 30000;
 unsigned char __gnat_objlist_file_supported = 1;
 char __gnat_shared_libgnat_default = STATIC;
 char __gnat_shared_libgcc_default = STATIC;
-unsigned char __gnat_using_gnu_linker = 1;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
@@ -115,19 +99,17 @@ 
 unsigned char __gnat_objlist_file_supported = 1;
 char __gnat_shared_libgnat_default = STATIC;
 char __gnat_shared_libgcc_default = STATIC;
-unsigned char __gnat_using_gnu_linker = 0;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
 
 #elif defined (__FreeBSD__)
-const char *__gnat_object_file_option = "";
+const char *__gnat_object_file_option = "-Wl,@";
 const char *__gnat_run_path_option = "-Wl,-rpath,";
 char __gnat_shared_libgnat_default = STATIC;
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 8192;
 unsigned char __gnat_objlist_file_supported = 1;
-unsigned char __gnat_using_gnu_linker = 1;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
@@ -139,19 +121,17 @@ 
 char __gnat_shared_libgcc_default = SHARED;
 int __gnat_link_max = 262144;
 unsigned char __gnat_objlist_file_supported = 1;
-unsigned char __gnat_using_gnu_linker = 0;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 1;
 const char *__gnat_default_libgcc_subdir = "lib";
 
 #elif defined (linux) || defined(__GLIBC__)
-const char *__gnat_object_file_option = "";
+const char *__gnat_object_file_option = "-Wl,@";
 const char *__gnat_run_path_option = "-Wl,-rpath,";
 char __gnat_shared_libgnat_default = STATIC;
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 8192;
 unsigned char __gnat_objlist_file_supported = 1;
-unsigned char __gnat_using_gnu_linker = 1;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 #if defined (__x86_64)
@@ -174,7 +154,6 @@ 
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 15000;
 const unsigned char __gnat_objlist_file_supported = 1;
-unsigned char __gnat_using_gnu_linker = 0;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
@@ -183,13 +162,12 @@ 
 /*  These are the settings for all systems that use gnu ld. GNU style response
     file is supported, the shared library default is STATIC.  */
 
-const char *__gnat_object_file_option = "";
+const char *__gnat_object_file_option = "-Wl,@";
 const char *__gnat_run_path_option = "";
 char __gnat_shared_libgnat_default = STATIC;
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 8192;
 unsigned char __gnat_objlist_file_supported = 1;
-unsigned char __gnat_using_gnu_linker = 1;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
@@ -201,7 +179,6 @@ 
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 2147483647;
 unsigned char __gnat_objlist_file_supported = 0;
-unsigned char __gnat_using_gnu_linker = 0;
 const char *__gnat_object_library_extension = ".olb";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
@@ -213,7 +190,6 @@ 
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 2147483647;
 unsigned char __gnat_objlist_file_supported = 0;
-unsigned char __gnat_using_gnu_linker = 0;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 #if defined (__sparc_v9__) || defined (__sparcv9)
@@ -231,7 +207,6 @@ 
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 2147483647;
 unsigned char __gnat_objlist_file_supported = 0;
-unsigned char __gnat_using_gnu_linker = 0;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
@@ -246,7 +221,6 @@ 
 char __gnat_shared_libgcc_default = STATIC;
 int __gnat_link_max = 2147483647;
 unsigned char __gnat_objlist_file_supported = 0;
-unsigned char __gnat_using_gnu_linker = 0;
 const char *__gnat_object_library_extension = ".a";
 unsigned char __gnat_separate_run_path_options = 0;
 const char *__gnat_default_libgcc_subdir = "lib";
Index: testsuite/gnat.dg/lto12.adb
===================================================================
--- testsuite/gnat.dg/lto13.adb	(revision 0)
+++ testsuite/gnat.dg/lto13.adb	(revision 0)
@@ -0,0 +1,7 @@ 
+-- { dg-do link }
+-- { dg-options "-largs -f -margs -flto" { target lto } }
+
+procedure Lto13 is
+begin
+  null;
+end;