LI77683: Incorrect DWARF for threadprivate common block

XL Fortran for Blue Gene/Q Fix Pack 12 (May 2015 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 14 (May 2016 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 15 (October 2017 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 7 (February 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 8 (May 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 9 (August 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 10 (November 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 11 (February 2015 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 13 (August 2015 Update) for 14.1

APAR status

• Closed as program error.

Error description

• Incorrect DWARF information is found for threadprivate common
  block in TLS.
  
  Consider the following test case.
  
  ===== TESTCASE:
  $cat tx_omp_f_threadprivate.f90
  ! "Parallel Programming in OpenMP" ISBN 1-55860-671-8
  ! Copyright 2001 by Academic Press
  ! Example 4.7 (pp 104-105) with slight modifications
  
        program correct
        integer omp_get_num_threads, omp_get_thread_num
        integer iarray(100), N, nthreads, iam, chunk, istart, iend
        common /bounds/ istart, iend
  !$omp threadprivate(/bounds/)
  
        N = 100
  !$omp parallel private(nthreads, iam, chunk)
  
        ! Compute the subset of iterations executed by each thread
        nthreads = omp_get_num_threads()
        iam = omp_get_thread_num()
        chunk = (N + nthreads - 1)/nthreads
        istart = iam * chunk + 1
        iend = min((iam + 1) * chunk, N)
  !      print *, nthreads, iam, chunk, istart, iend
  
        call work(iarray)
  !$omp end parallel
        print *
        print *, iarray
        PRINT *, "Hello, World."
        end
  
        subroutine work(iarray)
  
        integer iarray(100), istart, iend, i
        common /bounds/ istart, iend
  !$omp threadprivate(/bounds/)
  
        do i = istart, iend
            iarray(i) = i * i
        enddo
        return
        end
  
  
  bgxlf90_r -qsmp=omp:noauto:noopt -g -q64 -qnosave
  tx_omp_f_threadprivate.f90 -o tx_omp_f_threadprivate.bgq
  
  readelf --debug-dump=info tx_omp_f_threadprivate.bgq|grep
  DW_TAG_common_block -A18
  
  The resulted
  
  <2><18d>: Abbrev Number: 12 (DW_TAG_common_block)
      <18e>   DW_AT_sibling     : 0x0 0x1e2
      <196>   DW_AT_location    : 9 byte block: 3 0 0 0 0 10 1 12
  78      (DW_OP_addr: 10011278)
      <1a0>   DW_AT_name        : bounds
  
  The DWARF DW_AT_location does not reflect the fact that the
  common block named /bounds/ is in TLS. The members of the
  common block should be offsets from the beginning of /bounds/,
  which is in TLS.
  

Local fix

• n/a
  

Problem summary

• PROBLEM DESCRIPTION: The DWARF DW_AT_location does not reflect
  the fact that the common block member is in TLS.
  
  USERS AFFECTED: users who want to debug with -qsmp option
  

Problem conclusion

• Added the correct location attribute to the dwarf info and the
  issue was fixed
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  LI77823 IV56781

Fix information

• Fixed component name

  XL FORTRAN FOR

• Fixed component ID

  5799AH100

Applicable component levels

• RE10 PSY

     UP