[Bug debug/40823] New: debug info points to unexpected line

["jv244 at cam dot ac dot uk" <gcc-bugzilla at gcc dot gnu dot org>]

the observation is that profiling tools (like callgrind/valgrind) will assign a
fraction of the instructions to line 2 (PUBLIC S1) in a profile, similarly a
debugger will jump to line 2 if one steps through the execution of this
program.   This is not particularly intuitive (since this line just specifies
an attribute and is not executed), and doesn't happen if e.g. ifort is used for
compilation.

MODULE M1
 PUBLIC S1
CONTAINS
 SUBROUTINE S1(A,n)
  INTEGER :: n
  INTEGER :: A(n,n,n,n)
  A(1,1,1,1)=0
 END SUBROUTINE S1
END MODULE M1

PROGRAM TEST
  USE M1
  INTEGER :: A(2,2,2,2),i
  DO i=1,10000000
     CALL S1(A,2)
  ENDDO
END PROGRAM TEST


-- 
           Summary: debug info points to unexpected line
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jv244 at cam dot ac dot uk


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40823