https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63561
Bug ID: 63561
Summary: gfortran runtime hang on function print-stmt
Product: gcc
Version: 4.9.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgomp
Assignee: unassigned at gcc dot gnu.org
Reporter: sidio47 at hotmail dot com
CC: jakub at gcc dot gnu.org
Created attachment 33735
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33735&action=edit
Source code demonstrating runtime hang.
Attached is a Fortran program that attempts to print the output of a function
from a module. From my tests, when certain compile libraries are used, the
program will wait indefinitely using all versions of GCC (gfortran) that I have
access to (4.9.1, 4.8.3, 4.7.1) on three different systems:
1.) Linux 3.16.3-200.fc20.x86_64 #1 SMP Wed Sep 17 22:34:21 UTC 2014 x86_64
x86_64 x86_64 GNU/Linux
2.) Linux 2.6.32-431.17.1.el6.x86_64 #1 SMP Wed May 7 23:32:49 UTC 2014 x86_64
x86_64 x86_64 GNU/Linux
3.) Linux 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64
x86_64 x86_64 GNU/Linux
The code has no openmp or mpi calls.
I believe the module to be irrelevant; i.e. the hang still occurs with an
external function.
1.) Plain old vanilla gfortran works as intended.
2.) Adding the -fopenmp flag will cause it to hang.
3.) Adding the mpif90 wrapper from MVAPICH2 will cause it to hang.
i.e:
1.) gfortran silly.F90 -o silly && ./silly <--- Works
2.) gfortran silly.F90 -o silly -fopenmp && ./silly <--- Hangs
3.) mpif90 silly.F90 -o silly && ./silly <--- Hangs
