On Tue, Apr 9, 2024 at 10:25 AM Andrew Pinski <pins...@gmail.com> wrote:
>
>
>
> On Tue, Apr 9, 2024, 10:07 H.J. Lu <hjl.to...@gmail.com> wrote:
>>
>> Since Glibc 2.34 all pthreads symbols are defined directly in libc not
>> libpthread, and since Glibc 2.32 we have used __libc_single_threaded to
>> avoid unnecessary locking in single-threaded programs. This means there
>> is no reason to avoid linking to libpthread now, and so no reason to use
>> weak symbols defined in gthr-posix.h for all the pthread_xxx functions.
>
>
>
> First you forgot to cc fortran@. Second the issue is in gthrd-posix.h which
> should be fixed instead of libgfortran since the issue will also be seen with
> libobjc, and the other users of gthrd.
Weak symbol reference to pthread doesn't fail for all static executables.
Fixing it on a per-library basis is one approach.
> Note the fix for libstdc++ was also done in the wrong location too and should
> have done once and for all in gthrd-posix.h.
>
>
> Thanks,
> Andrew
>
>>
>> Also add prune_warnings to libgomp.exp to prune glibc static link warning:
>>
>> .*: warning: Using 'dlopen' in statically linked applications requires at
>> runtime the shared libraries from the glibc version us ed for linking
>>
>> libgfortran/
>>
>> PR libgfortran/114646
>> * acinclude.m4: Define GTHREAD_USE_WEAK 0 for glibc 2.34 or
>> above on Linux.
>> * configure: Regenerated.
>>
>> libgomp/
>>
>> PR libgfortran/114646
>> * testsuite/lib/libgomp.exp (prune_warnings): New.
>> * testsuite/libgomp.fortran/pr114646-1.f90: New test.
>> * testsuite/libgomp.fortran/pr114646-2.f90: Likewise.
>> ---
>> libgfortran/acinclude.m4 | 14 +++++++++
>> libgfortran/configure | 29 +++++++++++++++++++
>> libgomp/testsuite/lib/libgomp.exp | 14 +++++++++
>> .../testsuite/libgomp.fortran/pr114646-1.f90 | 11 +++++++
>> .../testsuite/libgomp.fortran/pr114646-2.f90 | 22 ++++++++++++++
>> 5 files changed, 90 insertions(+)
>> create mode 100644 libgomp/testsuite/libgomp.fortran/pr114646-1.f90
>> create mode 100644 libgomp/testsuite/libgomp.fortran/pr114646-2.f90
>>
>> diff --git a/libgfortran/acinclude.m4 b/libgfortran/acinclude.m4
>> index a73207e5465..f4642494c4f 100644
>> --- a/libgfortran/acinclude.m4
>> +++ b/libgfortran/acinclude.m4
>> @@ -92,6 +92,20 @@ void foo (void);
>> AC_DEFINE(GTHREAD_USE_WEAK, 0,
>> [Define to 0 if the target shouldn't use #pragma weak])
>> ;;
>> + *-*-linux*)
>> + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
>> +#include <features.h>
>> +#if !__GLIBC_PREREQ(2, 34)
>> +#error glibc version is too old
>> +#endif
>> +]], [[]])],
>> + libgfor_cv_use_pragma_weak=no,
>> + libgfor_cv_use_pragma_weak=yes)
>> + if test $libgfor_cv_use_pragma_weak = no; then
>> + AC_DEFINE(GTHREAD_USE_WEAK, 0,
>> + [Define to 0 if the target shouldn't use #pragma weak])
>> + fi
>> + ;;
>> esac])
>>
>> dnl Check whether target effectively supports weakref
>> diff --git a/libgfortran/configure b/libgfortran/configure
>> index 774dd52fc95..1f477256b75 100755
>> --- a/libgfortran/configure
>> +++ b/libgfortran/configure
>> @@ -31057,6 +31057,35 @@ $as_echo "#define SUPPORTS_WEAK 1" >>confdefs.h
>>
>> $as_echo "#define GTHREAD_USE_WEAK 0" >>confdefs.h
>>
>> + ;;
>> + *-*-linux*)
>> + cat confdefs.h - <<_ACEOF >conftest.$ac_ext
>> +/* end confdefs.h. */
>> +
>> +#include <features.h>
>> +#if !__GLIBC_PREREQ(2, 34)
>> +#error glibc version is too old
>> +#endif
>> +
>> +int
>> +main ()
>> +{
>> +
>> + ;
>> + return 0;
>> +}
>> +_ACEOF
>> +if ac_fn_c_try_compile "$LINENO"; then :
>> + libgfor_cv_use_pragma_weak=no
>> +else
>> + libgfor_cv_use_pragma_weak=yes
>> +fi
>> +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
>> + if test $libgfor_cv_use_pragma_weak = no; then
>> +
>> +$as_echo "#define GTHREAD_USE_WEAK 0" >>confdefs.h
>> +
>> + fi
>> ;;
>> esac
>>
>> diff --git a/libgomp/testsuite/lib/libgomp.exp
>> b/libgomp/testsuite/lib/libgomp.exp
>> index cab926a798b..9cfa6d7b31d 100644
>> --- a/libgomp/testsuite/lib/libgomp.exp
>> +++ b/libgomp/testsuite/lib/libgomp.exp
>> @@ -54,6 +54,20 @@ set dg-do-what-default run
>>
>> set libgomp_compile_options ""
>>
>> +# Prune messages that aren't useful.
>> +
>> +proc prune_warnings { text } {
>> +
>> + verbose "prune_warnings: entry: $text" 2
>> +
>> + # Ignore warning from -static: warning: Using 'dlopen' in statically
>> linked applications requires at runtime the shared libraries from the glibc
>> version used for linking
>> + regsub -all "(^|\n)\[^\n\]*: warning: Using 'dlopen' in statically
>> linked\[^\n\]*" $text "" text
>> +
>> + verbose "prune_warnings: exit: $text" 2
>> +
>> + return $text
>> +}
>> +
>> #
>> # libgomp_init
>> #
>> diff --git a/libgomp/testsuite/libgomp.fortran/pr114646-1.f90
>> b/libgomp/testsuite/libgomp.fortran/pr114646-1.f90
>> new file mode 100644
>> index 00000000000..a48e6103343
>> --- /dev/null
>> +++ b/libgomp/testsuite/libgomp.fortran/pr114646-1.f90
>> @@ -0,0 +1,11 @@
>> +! PR libgfortran/114646
>> +! { dg-do run }
>> +! { dg-additional-options "-static" }
>> +
>> +!$OMP PARALLEL
>> +!$OMP CRITICAL
>> + write(6,*) "Hello world"
>> +!$OMP END CRITICAL
>> +!$OMP END PARALLEL
>> + write(6,*) "Done!"
>> +END
>> diff --git a/libgomp/testsuite/libgomp.fortran/pr114646-2.f90
>> b/libgomp/testsuite/libgomp.fortran/pr114646-2.f90
>> new file mode 100644
>> index 00000000000..8c0d7526f95
>> --- /dev/null
>> +++ b/libgomp/testsuite/libgomp.fortran/pr114646-2.f90
>> @@ -0,0 +1,22 @@
>> +! PR libgfortran/114646
>> +! { dg-do run }
>> +! { dg-additional-options "-static" }
>> +
>> + use omp_lib
>> + implicit none
>> + integer, parameter :: NT = 4
>> + integer :: nThreads(NT)
>> +
>> + print *, 'Call omp_set_dynamic'
>> +!$ call omp_set_dynamic(.false.)
>> + print *, 'Call omp_set_num_threads'
>> +!$ call omp_set_num_threads(NT)
>> + print *, 'Now enter the parallel region'
>> +
>> +!$omp parallel default(none) shared(nThreads)
>> + nThreads(omp_get_thread_num()+1) = omp_get_num_threads()
>> +!$omp end parallel
>> +
>> + print*, nThreads
>> +
>> + END
>> --
>> 2.44.0
>>
--
H.J.
