[Bug fortran/78827] New: Compiling gfortran.dg/charlen_03.f90 and gfortran.dg/charlen_10.f90 cause internal compiler error (regression)

["physiker at toast2 dot net" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78827

            Bug ID: 78827
           Summary: Compiling gfortran.dg/charlen_03.f90 and
                    gfortran.dg/charlen_10.f90 cause internal compiler
                    error (regression)
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: physiker at toast2 dot net
  Target Milestone: ---

There are to two regressions while running the gfortran.dg testsuite:
(See https://gcc.gnu.org/ml/gcc-testresults/2016-12/msg01567.html) 

FAIL: gfortran.dg/charlen_03.f90   -O   1 blank line(s) in output
FAIL: gfortran.dg/charlen_03.f90   -O  (internal compiler error)
FAIL: gfortran.dg/charlen_10.f90   -O   1 blank line(s) in output
FAIL: gfortran.dg/charlen_10.f90   -O  (internal compiler error)


LANG=C gfortran-7 -v -o charlen_03 charlen_03.f90 
Driving: gfortran-7 -v -o charlen_03 charlen_03.f90
-mmacosx-version-min=10.11.6 -asm_macosx_version_min=10.11 -l gfortran
-shared-libgcc
Using built-in specs.
COLLECT_GCC=gfortran-7
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-darwin15.6.0/7.0.0/lto-wrapper
Target: x86_64-apple-darwin15.6.0
Configured with: ../gcc/configure --enable-languages=c,c++,fortran,lto
--with-gmp=/sw --with-libiconv-prefix=/sw --with-isl=/sw --with-mpc=/sw
--with-system-zlib --program-suffix=-7
Thread model: posix
gcc version 7.0.0 20161215 (experimental) [trunk revision 243680] (GCC) 
COLLECT_GCC_OPTIONS='-v' '-o' 'charlen_03' '-mmacosx-version-min=10.11.6'
'-asm_macosx_version_min=10.11' '-shared-libgcc' '-mtune=core2'
 /usr/local/libexec/gcc/x86_64-apple-darwin15.6.0/7.0.0/f951 charlen_03.f90
-fPIC -quiet -dumpbase charlen_03.f90 -mmacosx-version-min=10.11.6 -mtune=core2
-auxbase charlen_03 -version -fintrinsic-modules-path
/usr/local/lib/gcc/x86_64-apple-darwin15.6.0/7.0.0/finclude -o
/var/folders/97/4qnhjhtn25s86s9hkz0h37_m0000gn/T//cc0FKK10.s
GNU Fortran (GCC) version 7.0.0 20161215 (experimental) [trunk revision 243680]
(x86_64-apple-darwin15.6.0)
        compiled by GNU C version 7.0.0 20161215 (experimental) [trunk revision
243680], GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version
0.15
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
GNU Fortran2008 (GCC) version 7.0.0 20161215 (experimental) [trunk revision
243680] (x86_64-apple-darwin15.6.0)
        compiled by GNU C version 7.0.0 20161215 (experimental) [trunk revision
243680], GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version
0.15
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
charlen_03.f90:5:39:

       character(:), allocatable :: x(n) ! { dg-error "must have a deferred
shape" }
                                       1
Error: Allocatable component of structure at (1) must have a deferred shape
f951: internal compiler error: Segmentation fault: 11

f951: internal compiler error: Abort trap: 6
gfortran-7: internal compiler error: Abort trap: 6 (program f951)
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

gfortran version 6.2.0:
LANG=C gfortran-fsf-6 -o charlen_03 charlen_03.f90
charlen_03.f90:5:39:

       character(:), allocatable :: x(n) ! { dg-error "must have a deferred
shape" }
                                       1
Error: Allocatable component of structure at (1) must have a deferred shape
(null):0: confused by earlier errors, bailing out