[Bug fortran/71730] New: ICE when character length specification uses an undefined variable

[bardeau at iram dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71730

            Bug ID: 71730
           Summary: ICE when character length specification uses an
                    undefined variable
           Product: gcc
           Version: 6.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bardeau at iram dot fr
  Target Milestone: ---

Hi,

the following code raises an ICE. The error was seen with gfortran 5.3.0 and
6.1.0.

Cheers



$ cat ice.f90
subroutine foo
  implicit none
  character(len=bar) :: a
end subroutine foo


$ gfortran ice.f90
ice.f90:1:0:

 subroutine foo

internal compiler error: in gfc_typenode_for_spec, at
fortran/trans-types.c:1064
0x6e981b gfc_typenode_for_spec(gfc_typespec*)                                   
        ../../srcdir/gcc/fortran/trans-types.c:1064                             
0x6e9b0f gfc_sym_type(gfc_symbol*)                                              
        ../../srcdir/gcc/fortran/trans-types.c:2160
0x69cf4c gfc_get_symbol_decl(gfc_symbol*)
        ../../srcdir/gcc/fortran/trans-decl.c:1574
0x69f907 generate_local_decl
        ../../srcdir/gcc/fortran/trans-decl.c:5220
0x69fcde expr_decls
        ../../srcdir/gcc/fortran/trans-decl.c:5168
0x5ee249 gfc_traverse_expr(gfc_expr*, gfc_symbol*, bool (*)(gfc_expr*,
gfc_symbol*, int*), int)
        ../../srcdir/gcc/fortran/expr.c:4148
0x69fc10 generate_expr_decls
        ../../srcdir/gcc/fortran/trans-decl.c:5175
0x69fc10 generate_dependency_declarations
        ../../srcdir/gcc/fortran/trans-decl.c:5190
0x69fc10 generate_local_decl
        ../../srcdir/gcc/fortran/trans-decl.c:5217
0x6686bb do_traverse_symtree
        ../../srcdir/gcc/fortran/symbol.c:3817
0x6a053a generate_local_vars
        ../../srcdir/gcc/fortran/trans-decl.c:5410
0x6a053a gfc_generate_function_code(gfc_namespace*)
        ../../srcdir/gcc/fortran/trans-decl.c:6089
0x639430 translate_all_program_units
        ../../srcdir/gcc/fortran/parse.c:5613
0x639430 gfc_parse_file()
        ../../srcdir/gcc/fortran/parse.c:5819
0x67a5c5 gfc_be_parse_file
        ../../srcdir/gcc/fortran/f95-lang.c:201
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.


$ gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/home/bardeau/Softs/gcc-6.1.0/libexec/gcc/x86_64-pc-linux-gnu/6.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../srcdir/configure --with-gmp=/home/bardeau/Softs
--prefix=/home/bardeau/Softs/gcc-6.1.0 --enable-languages=c,c++,fortran
Thread model: posix
gcc version 6.1.0 (GCC)