[Bug fortran/47839] New: ICE in dwarf2out.c:add_AT_specification

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47839

           Summary: ICE in dwarf2out.c:add_AT_specification
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: lto
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: rguenth@gcc.gnu.org


Building 459.GemsFDTD (and 416.gamess) with -O3 -ffast-math -flto -g ICEs
because the Fortran frontend seemingly puts imported variables in the
BLOCK tree of the imported function and does not mark them external.

The variable in question is huy_param from huygens_mod, imported from
nft_store

SUBROUTINE NFT_Store(Ex,Ey,Ez,Hx,Hy,Hz,t,ts)

USE excite_mod,  ONLY : excitation
USE huygens_mod, ONLY : Huy_param, HuyPulseType

and

MODULE Huygens_mod
...
real(kind=rfp), dimension(excite_max_no_param), PUBLIC :: Huy_param


I tried to create a small testcase but failed sofar.  It doesn't ICE
with -flto-partition=none but it does with -flto-partition=1to1.

With partially linking 459.GemsFDTD I get the ICE with

/abuild/rguenther/install-trunk/usr/local/bin/gfortran globalvar.f90 PEC.f90 -o
GemsFDTD -flto -flto-partition=none -r -nostdlib -O -g

which is then obviously related to a different variable.  Trying to
reduce the sources now.