[Bug fortran/54462] New: [4.8 Regression] Another "segmentation fault" after an error in COMMON statement after r190853

["dominiq at lps dot ens.fr" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54462

             Bug #: 54462
           Summary: [4.8 Regression] Another "segmentation fault" after an
                    error in COMMON statement after r190853
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dominiq@lps.ens.fr
                CC: burnus@net-b.de


After revision 190853 compiling the original test in pr29537 gives a
segmentation fault. A reduced test is

type a_t
  integer i
end type a_t

block data bd
  common c
end block data bd

common /a_t/ c
end

and the backtrace is

(gdb) run pr29537_red.f90
Starting program:
/opt/gcc/gcc4.8p-190863p3/libexec/gcc/x86_64-apple-darwin10.8.0/4.8.0/f951
pr29537_red.f90
pr29537_red.f90:5.13:

block data bd
             1   
Error: Unexpected BLOCK DATA statement at (1)
pr29537_red.f90:6.10:

  common c
          1   
Error: Unexpected COMMON statement at (1)

Program received signal SIGSEGV, Segmentation fault.
gfc_undo_symbols () at ../../p_work/gcc/fortran/symbol.c:2923
2923              st.name = st0->name;
(gdb) bt
#0  gfc_undo_symbols () at ../../p_work/gcc/fortran/symbol.c:2923
#1  0x0000000100077fa6 in reject_statement () at
../../p_work/gcc/fortran/parse.c:1747
#2  0x000000010007e226 in parse_progunit (st=<optimized out>) at
../../p_work/gcc/fortran/parse.c:4168
#3  0x000000010007f04f in gfc_parse_file () at
../../p_work/gcc/fortran/parse.c:4597
#4  0x00000001000be5c6 in gfc_be_parse_file () at
../../p_work/gcc/fortran/f95-lang.c:191
#5  0x000000010061e95f in compile_file () at ../../p_work/gcc/toplev.c:546
#6  0x0000000100620425 in toplev_main (argc=2, argv=0x7fff5fbfd778) at
../../p_work/gcc/toplev.c:1863
#7  0x000000010000aa44 in start () at
../../../p_work/libgcc/unwind-dw2-fde.c:1055