[PATCH] Kill unused variable `self' warnings

[PATCH] Kill unused variable `self' warnings

[Jakub Jelinek]

Hi!

Tested on IA-64, where there were no differences between libc.so and
libpthread.so built without and with this patch but in
.debug_info/.debug_line sections. But more than 80 warnings are gone.

2003-01-30  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/alpha/tls.h (THREAD_GETMEM, THREAD_GETMEM_NC,
	THREAD_SETMEM, THREAD_SETMEM_NC): Avoid warnings about unused self
	variable.
	* sysdeps/ia64/pt-machine.h (THREAD_GETMEM, THREAD_GETMEM_NC,
	THREAD_SETMEM, THREAD_SETMEM_NC): Likewise.
	* sysdeps/s390/s390-32/pt-machine.h (THREAD_GETMEM, THREAD_GETMEM_NC,
	THREAD_SETMEM, THREAD_SETMEM_NC): Likewise.
	* sysdeps/s390/s390-64/pt-machine.h (THREAD_GETMEM, THREAD_GETMEM_NC,
	THREAD_SETMEM, THREAD_SETMEM_NC): Likewise.
	* sysdeps/sh/pt-machine.h (THREAD_GETMEM, THREAD_GETMEM_NC,
	THREAD_SETMEM, THREAD_SETMEM_NC): Likewise.
	* sysdeps/sparc/sparc32/pt-machine.h (THREAD_GETMEM, THREAD_GETMEM_NC,
	THREAD_SETMEM, THREAD_SETMEM_NC): Likewise.
	* sysdeps/sparc/sparc64/pt-machine.h (THREAD_GETMEM, THREAD_GETMEM_NC,
	THREAD_SETMEM, THREAD_SETMEM_NC): Likewise.

--- libc/linuxthreads/sysdeps/alpha/tls.h.jj	2003-01-17 14:17:02.000000000 -0500
+++ libc/linuxthreads/sysdeps/alpha/tls.h	2003-01-30 09:04:34.000000000 -0500
@@ -114,10 +114,12 @@ typedef struct
    the compiler does its job and unifies the multiple
    __builtin_thread_pointer instances.  */
 
-#define THREAD_GETMEM(descr, member) THREAD_SELF->member
-#define THREAD_GETMEM_NC(descr, member) THREAD_SELF->member
-#define THREAD_SETMEM(descr, member, value) (THREAD_SELF->member = (value))
-#define THREAD_SETMEM_NC(descr, member, value) (THREAD_SELF->member = (value))
+#define THREAD_GETMEM(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
 
 # endif	/* HAVE_TLS_SUPPORT */
 #endif /* __ASSEMBLER__ */
--- libc/linuxthreads/sysdeps/ia64/pt-machine.h.jj	2003-01-12 03:39:10.000000000 -0500
+++ libc/linuxthreads/sysdeps/ia64/pt-machine.h	2003-01-30 09:06:21.000000000 -0500
@@ -64,10 +64,12 @@ register struct _pthread_descr_struct *_
 
 
 /* Access to data in the thread descriptor is easy.  */
-#define THREAD_GETMEM(descr, member) THREAD_SELF->member
-#define THREAD_GETMEM_NC(descr, member) THREAD_SELF->member
-#define THREAD_SETMEM(descr, member, value) THREAD_SELF->member = (value)
-#define THREAD_SETMEM_NC(descr, member, value) THREAD_SELF->member = (value)
+#define THREAD_GETMEM(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
 
 
 /* Memory barrier */
--- libc/linuxthreads/sysdeps/s390/s390-32/pt-machine.h.jj	2003-01-28 05:29:18.000000000 -0500
+++ libc/linuxthreads/sysdeps/s390/s390-32/pt-machine.h	2003-01-30 09:08:23.000000000 -0500
@@ -80,10 +80,12 @@ register char * stack_pointer __asm__ ("
 #endif
 
 /* Access to data in the thread descriptor is easy.  */
-#define THREAD_GETMEM(descr, member) THREAD_SELF->member
-#define THREAD_GETMEM_NC(descr, member) THREAD_SELF->member
-#define THREAD_SETMEM(descr, member, value) THREAD_SELF->member = (value)
-#define THREAD_SETMEM_NC(descr, member, value) THREAD_SELF->member = (value)
+#define THREAD_GETMEM(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
 
 /* We want the OS to assign stack addresses.  */
 #define FLOATING_STACKS 1
--- libc/linuxthreads/sysdeps/s390/s390-64/pt-machine.h.jj	2003-01-28 05:29:18.000000000 -0500
+++ libc/linuxthreads/sysdeps/s390/s390-64/pt-machine.h	2003-01-30 09:09:08.000000000 -0500
@@ -86,10 +86,12 @@ register char * stack_pointer __asm__ ("
 #endif
 
 /* Access to data in the thread descriptor is easy.  */
-#define THREAD_GETMEM(descr, member) THREAD_SELF->member
-#define THREAD_GETMEM_NC(descr, member) THREAD_SELF->member
-#define THREAD_SETMEM(descr, member, value) THREAD_SELF->member = (value)
-#define THREAD_SETMEM_NC(descr, member, value) THREAD_SELF->member = (value)
+#define THREAD_GETMEM(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
 
 /* We want the OS to assign stack addresses.  */
 #define FLOATING_STACKS 1
--- libc/linuxthreads/sysdeps/sh/pt-machine.h.jj	2002-10-02 02:19:45.000000000 -0400
+++ libc/linuxthreads/sysdeps/sh/pt-machine.h	2003-01-30 09:07:11.000000000 -0500
@@ -1,6 +1,6 @@
 /* Machine-dependent pthreads configuration and inline functions.
    SuperH version.
-   Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+   Copyright (C) 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Niibe Yutaka <gniibe@m17n.org>.
 
@@ -68,10 +68,12 @@ struct _pthread_descr_struct;
   ({ __asm__ __volatile__("ldc %0,gbr" : : "r" (descr));})
 
 /* Access to data in the thread descriptor is easy.  */
-#define THREAD_GETMEM(descr, member) THREAD_SELF->member
-#define THREAD_GETMEM_NC(descr, member) THREAD_SELF->member
-#define THREAD_SETMEM(descr, member, value) THREAD_SELF->member = (value)
-#define THREAD_SETMEM_NC(descr, member, value) THREAD_SELF->member = (value)
+#define THREAD_GETMEM(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
 #endif /* __ASSEMBLER__ */
 
 #endif /* pt-machine.h */
--- libc/linuxthreads/sysdeps/sparc/sparc32/pt-machine.h.jj	2003-01-27 15:47:07.000000000 -0500
+++ libc/linuxthreads/sysdeps/sparc/sparc32/pt-machine.h	2003-01-30 09:10:21.000000000 -0500
@@ -65,10 +65,12 @@ register struct _pthread_descr_struct *_
 #define INIT_THREAD_SELF(descr, nr)  (__thread_self = (descr))
 
 /* Access to data in the thread descriptor is easy.  */
-#define THREAD_GETMEM(descr, member) __thread_self->member
-#define THREAD_GETMEM_NC(descr, member) __thread_self->member
-#define THREAD_SETMEM(descr, member, value) __thread_self->member = (value)
-#define THREAD_SETMEM_NC(descr, member, value) __thread_self->member = (value)
+#define THREAD_GETMEM(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
 
 /* We want the OS to assign stack addresses.  */
 #define FLOATING_STACKS 1
--- libc/linuxthreads/sysdeps/sparc/sparc64/pt-machine.h.jj	2003-01-27 15:47:08.000000000 -0500
+++ libc/linuxthreads/sysdeps/sparc/sparc64/pt-machine.h	2003-01-30 09:10:50.000000000 -0500
@@ -87,10 +87,12 @@ __compare_and_swap (long int *p, long in
 }
 
 /* Access to data in the thread descriptor is easy.  */
-#define THREAD_GETMEM(descr, member) __thread_self->member
-#define THREAD_GETMEM_NC(descr, member) __thread_self->member
-#define THREAD_SETMEM(descr, member, value) __thread_self->member = (value)
-#define THREAD_SETMEM_NC(descr, member, value) __thread_self->member = (value)
+#define THREAD_GETMEM(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_GETMEM_NC(descr, member) (sizeof (descr), THREAD_SELF->member)
+#define THREAD_SETMEM(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
+#define THREAD_SETMEM_NC(descr, member, value) \
+  (sizeof (descr), THREAD_SELF->member = (value))
 
 /* We want the OS to assign stack addresses.  */
 #define FLOATING_STACKS 1

	Jakub

hack to get sysinfo initialized

[David Mosberger]

Yesterday, I managed to boostrap an ia64 machine with the new
light-weight syscall stub.  It's all working very well.  The main
issue I had with glibc was making sure that [r13-8] always contains a
valid sysinfo pointer.  To this end, I had to hack
linuxthreads/{manager,pthread}.c as shown below.  I suspect there is
something else wrong here, but to be honest, I don't quite understand
how the various INIT_TP macros etc.  are intended to be used for the
various configurations.  Would someone be kind enough to enlighten me?

For reference, here are the key-macros that I'm using in
linuxthreads/sysdeps/ia64/tls.h:

#  define TLS_INIT_TP(tcbp, secondcall)			\
  (__thread_self = (tcbp),				\
   THREAD_SELF->p_header.data.sysinfo = GL(dl_sysinfo),	\
   NULL)

#  define INIT_THREAD_SELF(descr, nr) \
  (__thread_self = (struct _pthread_descr_struct *)(descr) + 1)

#  define NONTLS_INIT_TP \
  do { 									\
    static const tcbhead_t nontls_init_tp = { .multiple_threads = 0 };	\
    __thread_self = (__typeof (__thread_self)) &nontls_init_tp;		\
  } while (0)

Thanks!

	--david

Index: linuxthreads/manager.c
===================================================================
RCS file: /cvs/glibc/libc/linuxthreads/manager.c,v
retrieving revision 1.90
diff -u -r1.90 manager.c
--- linuxthreads/manager.c	12 Jan 2003 08:42:38 -0000	1.90
+++ linuxthreads/manager.c	30 Jan 2003 06:28:23 -0000
@@ -645,6 +666,8 @@
 #endif
   new_thread->p_header.data.self = new_thread;
   new_thread->p_header.data.multiple_threads = 1;
+  /* XXX why isn't this done already??? */
+  new_thread->p_header.data.sysinfo = GL(dl_sysinfo);
   new_thread->p_tid = new_thread_id;
   new_thread->p_lock = &(__pthread_handles[sseg].h_lock);
   new_thread->p_cancelstate = PTHREAD_CANCEL_ENABLE;
Index: linuxthreads/pthread.c
===================================================================
RCS file: /cvs/glibc/libc/linuxthreads/pthread.c,v
retrieving revision 1.119
diff -u -r1.119 pthread.c
--- linuxthreads/pthread.c	16 Jan 2003 18:16:32 -0000	1.119
+++ linuxthreads/pthread.c	30 Jan 2003 06:28:23 -0000
@@ -353,6 +353,9 @@
 
   self = THREAD_SELF;
 
+  /* XXX why isn't this done already??? */
+  self->p_header.data.sysinfo = GL(dl_sysinfo);
+
   /* The memory for the thread descriptor was allocated elsewhere as
      part of the TLS allocation.  We have to initialize the data
      structure by hand.  This initialization must mirror the struct
@@ -614,6 +617,8 @@
   mgr->p_header.data.tcb = tcbp;
   mgr->p_header.data.self = mgr;
   mgr->p_header.data.multiple_threads = 1;
+  /* XXX why isn't this done already??? */
+  mgr->p_header.data.sysinfo = GL(dl_sysinfo);
   mgr->p_lock = &__pthread_handles[1].h_lock;
 # ifndef HAVE___THREAD
   mgr->p_errnop = &mgr->p_errno;

Re: hack to get sysinfo initialized

[Ulrich Drepper]

David Mosberger wrote:

> --- linuxthreads/manager.c	12 Jan 2003 08:42:38 -0000	1.90
> +++ linuxthreads/manager.c	30 Jan 2003 06:28:23 -0000
> @@ -645,6 +666,8 @@
>  #endif
>    new_thread->p_header.data.self = new_thread;
>    new_thread->p_header.data.multiple_threads = 1;
> +  /* XXX why isn't this done already??? */
> +  new_thread->p_header.data.sysinfo = GL(dl_sysinfo);

Very simple: because there is no support fpr dl_sysinfo in LinuxThreads.

-- 
--------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------

Re: hack to get sysinfo initialized

[David Mosberger]

>>>>> On Thu, 30 Jan 2003 08:53:22 -0800, Ulrich Drepper <drepper@redhat.com> said:

  Uli> David Mosberger wrote:
  >> --- linuxthreads/manager.c	12 Jan 2003 08:42:38 -0000	1.90
  >> +++ linuxthreads/manager.c	30 Jan 2003 06:28:23 -0000
  >> @@ -645,6 +666,8 @@
  >> #endif
  >> new_thread-> p_header.data.self = new_thread;
  >> new_thread-> p_header.data.multiple_threads = 1;
  >> +  /* XXX why isn't this done already??? */
  >> +  new_thread->p_header.data.sysinfo = GL(dl_sysinfo);

  Uli> Very simple: because there is no support fpr dl_sysinfo in LinuxThreads.

Is there a problem that prevents this from working properly ever?  The
few hacks I put in seem to work fine at least for "make check" and for
bootstrapping a machine.  (In the longer term it shouldn't matter
much, as soon enough we'll be using NPTL, but in the meantime, it is
nice to be able to test with the new syscall stuff without having to
switch to a different threading library.)

	--david

Re: hack to get sysinfo initialized

[Ulrich Drepper]

David Mosberger wrote:
> Is there a problem that prevents this from working properly ever?

LinuxThreads for x86 is meant for compatibility and adding something
like this which isn't very often just doesn't seem necessary.  If you
have a new kernel you want to run a decent thread library.  There is no
fundamental problem but it might just open another can of worms (i.e.,
it needs testing).

-- 
--------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------

Re: hack to get sysinfo initialized

[David Mosberger]

>>>>> On Thu, 30 Jan 2003 09:07:11 -0800, Ulrich Drepper <drepper@redhat.com> said:

  Uli> LinuxThreads for x86 is meant for compatibility and adding something
  Uli> like this which isn't very often just doesn't seem necessary.  If you
  Uli> have a new kernel you want to run a decent thread library.

Sure, I'd love to.  I thought the ia64 NPTL bits weren't quite ready yet.
But yes, it will be nice to have it.

  Uli> There is no fundamental problem but it might just open another
  Uli> can of worms (i.e., it needs testing).

I can see that, but unless I'm missing something, the sysinfo member
is always there in the thread descriptor.  Leaving it uninitialized
seems more dangerous than initializing it with a sane value, no?

	--david

Re: hack to get sysinfo initialized

[Jakub Jelinek]

On Thu, Jan 30, 2003 at 09:13:21AM -0800, David Mosberger wrote:
> >>>>> On Thu, 30 Jan 2003 09:07:11 -0800, Ulrich Drepper <drepper@redhat.com> said:
> 
>   Uli> LinuxThreads for x86 is meant for compatibility and adding something
>   Uli> like this which isn't very often just doesn't seem necessary.  If you
>   Uli> have a new kernel you want to run a decent thread library.
> 
> Sure, I'd love to.  I thought the ia64 NPTL bits weren't quite ready yet.
> But yes, it will be nice to have it.
> 
>   Uli> There is no fundamental problem but it might just open another
>   Uli> can of worms (i.e., it needs testing).
> 
> I can see that, but unless I'm missing something, the sysinfo member
> is always there in the thread descriptor.  Leaving it uninitialized
> seems more dangerous than initializing it with a sane value, no?

The current state of AT_SYSINFO stuff is that NPTL libc/libpthread on i686 uses
it and ld.so from both NPTL and linuxthreads builds set it up.
This is so that ld.so from linuxthreads build can load both linuxthreads
and NPTL libs.

	Jakub

Re: hack to get sysinfo initialized

[Ulrich Drepper]

David Mosberger wrote:


> Leaving it uninitialized
> seems more dangerous than initializing it with a sane value, no?

It's not more dangerous if no LinuxThreads port uses it.  The activation
for using sysinfo is in the nptl sources.

-- 
--------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------

Re: hack to get sysinfo initialized

[David Mosberger]

>>>>> On Thu, 30 Jan 2003 09:20:01 -0800, Ulrich Drepper <drepper@redhat.com> said:

  Uli> David Mosberger wrote:
  >> Leaving it uninitialized
  >> seems more dangerous than initializing it with a sane value, no?

  Uli> It's not more dangerous if no LinuxThreads port uses it.  The activation
  Uli> for using sysinfo is in the nptl sources.

Oh, I think I understand now: the normal libc never defines
USE_DL_SYSINFO on x86 and hence nothing changes.

OK, I suppose that's fine then.  I'll just continue to use my hacks
until NPTL is ready.

Thanks,

	--david

Re: [PATCH] Kill unused variable `self' warnings

[Ulrich Drepper]

Jakub Jelinek wrote:

> Tested on IA-64, where there were no differences between libc.so and
> libpthread.so built without and with this patch but in
> .debug_info/.debug_line sections. But more than 80 warnings are gone.

I'd rather like a gcc solution but since none is in sight I applied the
patch.  Thanks,

-- 
--------------.                        ,-.            444 Castro Street
Ulrich Drepper \    ,-----------------'   \ Mountain View, CA 94041 USA
Red Hat         `--' drepper at redhat.com `---------------------------

Re: [PATCH] Kill unused variable `self' warnings

[Richard Henderson]

On Thu, Jan 30, 2003 at 09:48:20AM -0800, Ulrich Drepper wrote:
> I'd rather like a gcc solution but since none is in sight I applied the
> patch.  Thanks,

Hmm?  What sort of "solution" is there for this?  The local variable
that was created /really/ wasn't used.  You got accurate information 
from the warning.


r~