Bug 288968 – sys-devel/gdb-7.0 fails to print contents of dummy arrays when using gfortran

• Status: RESOLVED UPSTREAM
• Product: Gentoo Linux

[Description Fred Krogh 2009-10-13 21:47:09 UTC]

Sorry, I've only checked this in ddd, but after switching back to gdb-6.8-r2 all is working again.

Reproducible: Always

Steps to Reproduce:
1. ddd program
2. Set breakpoint in subroutine
3. Try to print part of a dummy array

Actual Results:  
Print

no such vector element

Expected Results:  
Print out of array part that one attempted to print.

See above.

[Comment 1 Peter Alfredsen (RETIRED) 2009-10-23 20:59:53 UTC]

Testcase would be nice with step-by-step walkthrough of what you're doing.

[Comment 2 Fred Krogh 2009-10-23 21:34:42 UTC]

Try this little program:

      program test
c   Testing gdb for printing arrays
      double precision C(4,4)
      do J = 1, 4
        do I = 1, 4
          C(I,J) = dble(I+J)
        end do
      end do
      call sub(C, 4)
      stop
      end
      subroutine sub(C, IDC)
      double precision C(IDC,*)
      print '(''C(1,1), C(4,4):'', 1P, 2E12.5)', C(1,1), C(4,4)
      return
      end

gfortran -ggdb -o test test.f
gdb test
b 14
r
p c(4,4)
c
quit

Note that the debugger prints 5 for c(4,4) while it should print 8.

[Comment 3 Fred Krogh 2009-12-17 18:45:11 UTC]

Since I've had a lot of system updates, I've tried this again, and things have changed for some reason.  Now instead of printing the wrong value, it prints "no such vector element".  It does this even at the point of the subroutine call.  It does do "p c(4,1)@5" correctly (that is it prints (5, 3, 4, 5, 6)), but will not print c(5,1), or c(1,2).

I have now filed a bug at the gdb site.

[Comment 4 SpanKY 2010-03-15 23:55:12 UTC]

upstream is working on the issue

http://sourceware.org/ml/gdb-patches/2009-01/msg00251.html
http://sourceware.org/ml/gdb-patches/2010-03/msg00443.html