[Bug fortran/84394] New: compiler error when using modules with derived types in block data subprograms

[csolomon at lanl dot gov]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84394

            Bug ID: 84394
           Summary: compiler error when using modules with derived types
                    in block data subprograms
           Product: gcc
           Version: 8.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: csolomon at lanl dot gov
  Target Milestone: ---

Created attachment 43418
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43418&action=edit
Simplified reproducer of the error.

Configuration info:

gfortran -v
Using built-in specs.
COLLECT_GCC=/opt/local/codes/mcnp/csolomon/gcc-8-20180211-install/bin/gfortran
COLLECT_LTO_WRAPPER=/opt/local/codes/mcnp/csolomon/gcc-8-20180211-install/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --prefix
/opt/local/codes/mcnp/csolomon/gcc-8-20180211-install
Thread model: posix
gcc version 8.0.1 20180211 (experimental) (GCC)

Problem info:

When compiling a block data subprogram that uses a module containing a derived
type the error below is obtained.  An error (without as much detail) also
occurs with GCC 7.3.0, but does not occur with GCC 6.4.0.  A simplified
reproducer is attached. 

gfortran -Wall -Wextra block_data_bug.f90 -o test

in gfc_format_decoder, at fortran/error.c:943
0x597156 gfc_format_decoder
        ../../gcc/fortran/error.c:943
0x1583bf7 pp_format(pretty_printer*, text_info*)
        ../../gcc/pretty-print.c:1375
0x1574307 diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
        ../../gcc/diagnostic.c:984
0x76c2ba gfc_error_opt
        ../../gcc/fortran/error.c:1308
0x76d7b0 gfc_error(char const*, ...)
        ../../gcc/fortran/error.c:1337
0x7f911f check_conflict
        ../../gcc/fortran/symbol.c:485
0x7dbb3a resolve_component
        ../../gcc/fortran/resolve.c:13642
0x7dc29a resolve_fl_derived0
        ../../gcc/fortran/resolve.c:14018
0x7dc867 resolve_fl_derived0
        ../../gcc/fortran/resolve.c:14162
0x7dc867 resolve_fl_derived
        ../../gcc/fortran/resolve.c:14140
0x7d9127 resolve_symbol
        ../../gcc/fortran/resolve.c:14514
0x7fa612 do_traverse_symtree
        ../../gcc/fortran/symbol.c:4157
0x7d3123 resolve_types
        ../../gcc/fortran/resolve.c:16415
0x7d819c gfc_resolve(gfc_namespace*)
        ../../gcc/fortran/resolve.c:16529
0x7c5fa6 gfc_parse_file()
        ../../gcc/fortran/parse.c:6262
0x80c6df gfc_be_parse_file
        ../../gcc/fortran/f95-lang.c:204
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