[PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Will Newton]

On Ubuntu the compiler passes --as-needed to the linker which means
no DT_NEEDED entry is added for libpthread when building the TLS
tests. This causes the test to fail as a libpthread is required to
look up TLS variables. Add some calls to pthread functions to make
sure libpthread is linked.

gdb/testsuite/ChangeLog:

2013-06-07  Will Newton  <will.newton@linaro.org>

	* gdb.threads/tls-nodebug.c: Call pthread_self to ensure
	the test is linked against pthreads.
	* gdb.threads/tls-var-main.c: Likewise.
	* gdb.threads/tls-shared.c: Call pthread_testcancel to
	ensure the test is linked against pthreads.
---
 gdb/testsuite/gdb.threads/tls-nodebug.c  | 2 +-
 gdb/testsuite/gdb.threads/tls-shared.c   | 4 ++++
 gdb/testsuite/gdb.threads/tls-var-main.c | 4 +++-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/gdb/testsuite/gdb.threads/tls-nodebug.c b/gdb/testsuite/gdb.threads/tls-nodebug.c
index 73d96f0..10aa8c8 100644
--- a/gdb/testsuite/gdb.threads/tls-nodebug.c
+++ b/gdb/testsuite/gdb.threads/tls-nodebug.c
@@ -6,5 +6,5 @@ __thread int thread_local = 42;

 int main(void)
 {
-  return 0;
+  return pthread_self();
 }
diff --git a/gdb/testsuite/gdb.threads/tls-shared.c b/gdb/testsuite/gdb.threads/tls-shared.c
index d4f8e5c..1ef7949 100644
--- a/gdb/testsuite/gdb.threads/tls-shared.c
+++ b/gdb/testsuite/gdb.threads/tls-shared.c
@@ -1,6 +1,10 @@
+
+#include <pthread.h>
+
 __thread int i_tls = 1;
 int foo ()
 {
+  pthread_testcancel();
   return i_tls;
 }

diff --git a/gdb/testsuite/gdb.threads/tls-var-main.c b/gdb/testsuite/gdb.threads/tls-var-main.c
index 34a2522..4728ea3 100644
--- a/gdb/testsuite/gdb.threads/tls-var-main.c
+++ b/gdb/testsuite/gdb.threads/tls-var-main.c
@@ -15,8 +15,10 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

+#include <pthread.h>
+
 int
 main (void)
 {
-  return 0;
+  return pthread_self();
 }
-- 
1.8.1.4

Re: [PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Andrew Pinski]

On Fri, Jun 7, 2013 at 11:40 AM, Will Newton <will.newton@linaro.org> wrote:
>
> On Ubuntu the compiler passes --as-needed to the linker which means
> no DT_NEEDED entry is added for libpthread when building the TLS
> tests. This causes the test to fail as a libpthread is required to
> look up TLS variables. Add some calls to pthread functions to make
> sure libpthread is linked.


I think this should be an debian/Ubuntu local only patch as the
default for FSF GCC/binutils is not to pass --as-needed.

Thanks,
Andrew

>
> gdb/testsuite/ChangeLog:
>
> 2013-06-07  Will Newton  <will.newton@linaro.org>
>
>         * gdb.threads/tls-nodebug.c: Call pthread_self to ensure
>         the test is linked against pthreads.
>         * gdb.threads/tls-var-main.c: Likewise.
>         * gdb.threads/tls-shared.c: Call pthread_testcancel to
>         ensure the test is linked against pthreads.
> ---
>  gdb/testsuite/gdb.threads/tls-nodebug.c  | 2 +-
>  gdb/testsuite/gdb.threads/tls-shared.c   | 4 ++++
>  gdb/testsuite/gdb.threads/tls-var-main.c | 4 +++-
>  3 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/gdb/testsuite/gdb.threads/tls-nodebug.c b/gdb/testsuite/gdb.threads/tls-nodebug.c
> index 73d96f0..10aa8c8 100644
> --- a/gdb/testsuite/gdb.threads/tls-nodebug.c
> +++ b/gdb/testsuite/gdb.threads/tls-nodebug.c
> @@ -6,5 +6,5 @@ __thread int thread_local = 42;
>
>  int main(void)
>  {
> -  return 0;
> +  return pthread_self();
>  }
> diff --git a/gdb/testsuite/gdb.threads/tls-shared.c b/gdb/testsuite/gdb.threads/tls-shared.c
> index d4f8e5c..1ef7949 100644
> --- a/gdb/testsuite/gdb.threads/tls-shared.c
> +++ b/gdb/testsuite/gdb.threads/tls-shared.c
> @@ -1,6 +1,10 @@
> +
> +#include <pthread.h>
> +
>  __thread int i_tls = 1;
>  int foo ()
>  {
> +  pthread_testcancel();
>    return i_tls;
>  }
>
> diff --git a/gdb/testsuite/gdb.threads/tls-var-main.c b/gdb/testsuite/gdb.threads/tls-var-main.c
> index 34a2522..4728ea3 100644
> --- a/gdb/testsuite/gdb.threads/tls-var-main.c
> +++ b/gdb/testsuite/gdb.threads/tls-var-main.c
> @@ -15,8 +15,10 @@
>     You should have received a copy of the GNU General Public License
>     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
>
> +#include <pthread.h>
> +
>  int
>  main (void)
>  {
> -  return 0;
> +  return pthread_self();
>  }
> --
> 1.8.1.4
>

Re: [PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Will Newton]

On 12 June 2013 00:02, Andrew Pinski <pinskia@gmail.com> wrote:
> On Fri, Jun 7, 2013 at 11:40 AM, Will Newton <will.newton@linaro.org> wrote:
>>
>> On Ubuntu the compiler passes --as-needed to the linker which means
>> no DT_NEEDED entry is added for libpthread when building the TLS
>> tests. This causes the test to fail as a libpthread is required to
>> look up TLS variables. Add some calls to pthread functions to make
>> sure libpthread is linked.
>
>
> I think this should be an debian/Ubuntu local only patch as the
> default for FSF GCC/binutils is not to pass --as-needed.

I admit the change is a little, erm, weird, but my hope was to avoid
causing pain to people who build gdb on Ubuntu. This isn't just Ubunto
or Debian developers but Ubuntu or Debian users that happen to have
downloaded a gdb tarball from gnu.org. Similar test failures in
binutils have been worked around by adding -Wl,--no-as-needed which we
could also do here, but I was concerned that this may break non-gcc
compilers.

--
Will Newton
Toolchain Working Group, Linaro

Re: [PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Joel Brobecker]

> > I think this should be an debian/Ubuntu local only patch as the
> > default for FSF GCC/binutils is not to pass --as-needed.
> 
> I admit the change is a little, erm, weird, but my hope was to avoid
> causing pain to people who build gdb on Ubuntu. This isn't just Ubunto
> or Debian developers but Ubuntu or Debian users that happen to have
> downloaded a gdb tarball from gnu.org. Similar test failures in
> binutils have been worked around by adding -Wl,--no-as-needed which we
> could also do here, but I was concerned that this may break non-gcc
> compilers.

I tend to agree that it can be potentially useful, and since it does
not appear to be very disruptive, I find it acceptable in principle.
I just haven't had time to look into it in more details...

-- 
Joel

Re: [PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Tom Tromey]

Andrew> I think this should be an debian/Ubuntu local only patch as the
Andrew> default for FSF GCC/binutils is not to pass --as-needed.

If that is the only reason, then I think it is still ok in principle to
use the patch.  It won't hurt the FSF default case.

Tom

Re: [PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Tom Tromey]

>>>>> "Will" == Will Newton <will.newton@linaro.org> writes:

Will>  int main(void)
Will>  {
Will> -  return 0;
Will> +  return pthread_self();

I think it is possible according to POSIX for pthread_t to be a pointer
type.  It seems like it would be safer to just use a call to
pthread_testcancel in all these tests.

Tom

Re: [PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Mark Kettenis]

> From: Tom Tromey <tromey@redhat.com>
> Date: Wed, 17 Jul 2013 12:18:25 -0600
> 
> >>>>> "Will" == Will Newton <will.newton@linaro.org> writes:
> 
> Will>  int main(void)
> Will>  {
> Will> -  return 0;
> Will> +  return pthread_self();
> 
> I think it is possible according to POSIX for pthread_t to be a pointer
> type.

It is on OpenBSD.

Re: [PATCH] gdb/testsuite/gdb.threads: Make sure TLS tests link against pthreads.

[Will Newton]

On 17 July 2013 19:18, Tom Tromey <tromey@redhat.com> wrote:
>
> >>>>> "Will" == Will Newton <will.newton@linaro.org> writes:
>
> Will>  int main(void)
> Will>  {
> Will> -  return 0;
> Will> +  return pthread_self();
>
> I think it is possible according to POSIX for pthread_t to be a pointer
> type.  It seems like it would be safer to just use a call to
> pthread_testcancel in all these tests.

Yes, that's true. I'll respin the patch, thanks for the review!


--
Will Newton
Toolchain Working Group, Linaro