Re: __attribute__ (__cleanup__) vs. _Unwind_Resume

[Thomas Schwinge <thomas at schwinge dot name>]

Hello!

On Mon, Apr 20, 2009 at 12:29:02PM -0700, Ulrich Drepper wrote:
> Thomas Schwinge wrote:
> > This came up when Ulrich corrected sysdeps/posix/readv.c and writev.c for
> > proper cancellation handling using __attribute__ (__cleanup__).  Linux
> > doesn't have this problem, as sysdeps/unix/sysv/linux/readv.c and
> > writev.c don't have to clean-up
> 
> Not in these files, but in preadv.c etc.

For easy reference, here is the error message:

    /home/tschwinge/tmp/glibc/tschwinge--Roger_Whittaker.build/libc_pic.os: In function `ifree':
    /media/data/home/tschwinge/tmp/glibc/tschwinge--Roger_Whittaker/misc/../sysdeps/posix/readv.c:32: undefined reference to `_Unwind_Resume'
    /home/tschwinge/tmp/glibc/tschwinge--Roger_Whittaker.build/libc_pic.os: In function `ifree':
    /media/data/home/tschwinge/tmp/glibc/tschwinge--Roger_Whittaker/misc/../sysdeps/posix/writev.c:32: undefined reference to `_Unwind_Resume'
    /home/tschwinge/tmp/glibc/tschwinge--Roger_Whittaker.build/libc_pic.os:(.data.DW.ref.__gcc_personality_v0[DW.ref.__gcc_personality_v0]+0x0): undefined reference to `__gcc_personality_v0'
    collect2: ld returned 1 exit status
    make[1]: *** [/home/tschwinge/tmp/glibc/tschwinge--Roger_Whittaker.build/libc.so] Error 1


> > One possibility to fix this would be to add -lgcc_eh to libc.so-gnulib in
> > Makeconfig (I don't know yet if that is legitimate), or perhaps, instead
> > of that, we should introduce / use something like
> > nptl/sysdeps/pthread/unwind-resume.c?
> 
> The later, probably.  This is how this work on Linux.

In later emails, we (Ulrich, Roland, I) agreed to do it this way; here is
a patch.


Generalize unwind-resume support for GNU.

2010-03-29  Thomas Schwinge  <thomas@schwinge.name>

	* nptl/sysdeps/pthread/unwind-resume.c: Move...
	* sysdeps/gnu/unwind-resume.c: ... here.
	(init): Generalize a string.
	* nptl/sysdeps/pthread/rt-unwind-resume.c: Move...
	* sysdeps/gnu/rt-unwind-resume.c: ... here.
	* nptl/sysdeps/pthread/Makefile: Move handling of unwind-resume.c and
	rt-unwind-resume.c to...
	* sysdeps/gnu/Makefile: ... here.

 nptl/sysdeps/pthread/Makefile           |   12 +-----
 nptl/sysdeps/pthread/rt-unwind-resume.c |    1 -
 nptl/sysdeps/pthread/unwind-resume.c    |   65 -------------------------------
 sysdeps/gnu/Makefile                    |   18 ++++++++-
 sysdeps/gnu/rt-unwind-resume.c          |    1 +
 sysdeps/gnu/unwind-resume.c             |   65 +++++++++++++++++++++++++++++++
 6 files changed, 84 insertions(+), 78 deletions(-)

diff --git a/nptl/sysdeps/pthread/Makefile b/nptl/sysdeps/pthread/Makefile
index 72550d7..32322e1 100644
--- a/nptl/sysdeps/pthread/Makefile
+++ b/nptl/sysdeps/pthread/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 2002,2003,2004,2006 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003, 2004, 2006, 2010 Free Software Foundation, Inc.
 # This file is part of the GNU C Library.
 # Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -17,21 +17,13 @@
 # Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 # 02111-1307 USA.
 
-ifeq ($(subdir),csu)
-routines += unwind-resume
-shared-only-routines += unwind-resume
-CFLAGS-unwind-resume.c += -fexceptions -fasynchronous-unwind-tables
-endif
-
 ifeq ($(subdir),nptl)
 libpthread-sysdep_routines += errno-loc
 endif
 
 ifeq ($(subdir),rt)
-librt-sysdep_routines += timer_routines librt-cancellation rt-unwind-resume
-librt-shared-only-routines += rt-unwind-resume
+librt-sysdep_routines += timer_routines librt-cancellation
 CFLAGS-librt-cancellation.c += -fexceptions -fasynchronous-unwind-tables
-CFLAGS-rt-unwind-resume.c += -fexceptions -fasynchronous-unwind-tables
 
 ifeq (yes,$(build-shared))
 $(objpfx)tst-timer: $(objpfx)librt.so $(shared-thread-library)
diff --git a/nptl/sysdeps/pthread/rt-unwind-resume.c b/nptl/sysdeps/pthread/rt-unwind-resume.c
deleted file mode 100644
index 743e675..0000000
--- a/nptl/sysdeps/pthread/rt-unwind-resume.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <unwind-resume.c>
diff --git a/nptl/sysdeps/pthread/unwind-resume.c b/nptl/sysdeps/pthread/unwind-resume.c
deleted file mode 100644
index 69f3e04..0000000
--- a/nptl/sysdeps/pthread/unwind-resume.c
+++ /dev/null
@@ -1,65 +0,0 @@
-/* Copyright (C) 2003 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Jakub Jelinek <jakub@redhat.com>.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public License as
-   published by the Free Software Foundation; either version 2.1 of the
-   License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; see the file COPYING.LIB.  If not,
-   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
-
-#include <dlfcn.h>
-#include <stdio.h>
-#include <unwind.h>
-#include <libgcc_s.h>
-
-static void (*libgcc_s_resume) (struct _Unwind_Exception *exc);
-static _Unwind_Reason_Code (*libgcc_s_personality)
-  (int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *,
-   struct _Unwind_Context *);
-
-static void
-init (void)
-{
-  void *resume, *personality;
-  void *handle;
-
-  handle = __libc_dlopen (LIBGCC_S_SO);
-
-  if (handle == NULL
-      || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL
-      || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL)
-    __libc_fatal (LIBGCC_S_SO " must be installed for pthread_cancel to work\n");
-
-  libgcc_s_resume = resume;
-  libgcc_s_personality = personality;
-}
-
-void
-_Unwind_Resume (struct _Unwind_Exception *exc)
-{
-  if (__builtin_expect (libgcc_s_resume == NULL, 0))
-    init ();
-  libgcc_s_resume (exc);
-}
-
-_Unwind_Reason_Code
-__gcc_personality_v0 (int version, _Unwind_Action actions,
-		      _Unwind_Exception_Class exception_class,
-                      struct _Unwind_Exception *ue_header,
-                      struct _Unwind_Context *context)
-{
-  if (__builtin_expect (libgcc_s_personality == NULL, 0))
-    init ();
-  return libgcc_s_personality (version, actions, exception_class,
-			       ue_header, context);
-}
diff --git a/sysdeps/gnu/Makefile b/sysdeps/gnu/Makefile
index 5b9a0a5..24d56cb 100644
--- a/sysdeps/gnu/Makefile
+++ b/sysdeps/gnu/Makefile
@@ -1,5 +1,6 @@
-# Copyright (C) 1996,1997,1998,1999,2001,2002,2003,2004,2005,2006
-#	Free Software Foundation, Inc.
+# Copyright (C) 1996, 1997, 1998, 1999, 2001, 2002, 2003, 2004, 2005, 2006,
+# 2010 Free Software Foundation, Inc.
+
 # This file is part of the GNU C Library.
 
 # The GNU C Library is free software; you can redistribute it and/or
@@ -77,3 +78,16 @@ endif
 ifeq ($(subdir),misc)
 sysdep_headers += sys/mtio.h
 endif
+
+
+ifeq ($(subdir),csu)
+routines += unwind-resume
+shared-only-routines += unwind-resume
+CFLAGS-unwind-resume.c += -fexceptions -fasynchronous-unwind-tables
+endif
+
+ifeq ($(subdir),rt)
+librt-sysdep_routines += rt-unwind-resume
+librt-shared-only-routines += rt-unwind-resume
+CFLAGS-rt-unwind-resume.c += -fexceptions -fasynchronous-unwind-tables
+endif
diff --git a/sysdeps/gnu/rt-unwind-resume.c b/sysdeps/gnu/rt-unwind-resume.c
new file mode 100644
index 0000000..743e675
--- /dev/null
+++ b/sysdeps/gnu/rt-unwind-resume.c
@@ -0,0 +1 @@
+#include <unwind-resume.c>
diff --git a/sysdeps/gnu/unwind-resume.c b/sysdeps/gnu/unwind-resume.c
new file mode 100644
index 0000000..a9ee4a9
--- /dev/null
+++ b/sysdeps/gnu/unwind-resume.c
@@ -0,0 +1,65 @@
+/* Copyright (C) 2003, 2010 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jakub Jelinek <jakub@redhat.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <dlfcn.h>
+#include <stdio.h>
+#include <unwind.h>
+#include <libgcc_s.h>
+
+static void (*libgcc_s_resume) (struct _Unwind_Exception *exc);
+static _Unwind_Reason_Code (*libgcc_s_personality)
+  (int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *,
+   struct _Unwind_Context *);
+
+static void
+init (void)
+{
+  void *resume, *personality;
+  void *handle;
+
+  handle = __libc_dlopen (LIBGCC_S_SO);
+
+  if (handle == NULL
+      || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL
+      || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL)
+    __libc_fatal (LIBGCC_S_SO " must be installed for proper functionality\n");
+
+  libgcc_s_resume = resume;
+  libgcc_s_personality = personality;
+}
+
+void
+_Unwind_Resume (struct _Unwind_Exception *exc)
+{
+  if (__builtin_expect (libgcc_s_resume == NULL, 0))
+    init ();
+  libgcc_s_resume (exc);
+}
+
+_Unwind_Reason_Code
+__gcc_personality_v0 (int version, _Unwind_Action actions,
+		      _Unwind_Exception_Class exception_class,
+                      struct _Unwind_Exception *ue_header,
+                      struct _Unwind_Context *context)
+{
+  if (__builtin_expect (libgcc_s_personality == NULL, 0))
+    init ();
+  return libgcc_s_personality (version, actions, exception_class,
+			       ue_header, context);
+}
-- 
tg: (62f8db6..) t/unwind-resume.c (depends on: baseline)


Regards,
 Thomas

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