[Bug c++/68722] New: internal compiler error: in merge_exception_specifiers, at cp/typeck2.c:2108

[regehr at cs dot utah.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68722

            Bug ID: 68722
           Summary: internal compiler error: in
                    merge_exception_specifiers, at cp/typeck2.c:2108
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: regehr at cs dot utah.edu
  Target Milestone: ---

Possibly a dup of PR68475

$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/home/regehr/z/compiler-install/gcc-r231259-install/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /home/regehr/z/compiler-source/gcc/configure
--prefix=/home/regehr/z/compiler-install/gcc-r231259-install
--disable-bootstrap --disable-multilib --enable-languages=c,c++
Thread model: posix
gcc version 6.0.0 20151204 (experimental) (GCC) 


$ cat hello.cpp
class A {
  &__loc
} class ios_base {
  A _M_ios_locale ios_base(ios_base &) template <_Traits> class basic_ios {
basic_ios basic_ios = operator=


$ g++ -std=c++11 hello.cpp -w
hello.cpp:2:4: error: ISO C++ forbids declaration of ‘__loc’ with no type
[-fpermissive]
   &__loc
    ^~~~~

hello.cpp:2:4: error: expected ‘;’ at end of member declaration
hello.cpp:3:1: error: expected ‘;’ after class definition
 } class ios_base {
 ^

hello.cpp:4:5: error: expected ‘;’ at end of member declaration
   A _M_ios_locale ios_base(ios_base &) template <_Traits> class basic_ios {
     ^~~~~~~~~~~~~

hello.cpp:4:38: error: expected ‘;’ at end of member declaration
   A _M_ios_locale ios_base(ios_base &) template <_Traits> class basic_ios {
                                      ^

hello.cpp:4:50: error: ‘_Traits’ has not been declared
   A _M_ios_locale ios_base(ios_base &) template <_Traits> class basic_ios {
                                                  ^~~~~~~

cc1plus: error: file ends in default argument
hello.cpp:5:31: error: expected ‘;’ at end of member declaration
 basic_ios basic_ios = operator=
                               ^

hello.cpp:5:31: error: expected ‘}’ at end of input
hello.cpp:5:31: error: expected unqualified-id at end of input
hello.cpp:5:31: error: expected ‘}’ at end of input
hello.cpp:5:31: error: use of deleted function ‘ios_base&
ios_base::operator=(const ios_base&)’
hello.cpp:3:9: internal compiler error: in merge_exception_specifiers, at
cp/typeck2.c:2108
 } class ios_base {
         ^~~~~~~~

0x667dd1 merge_exception_specifiers(tree_node*, tree_node*)
        /home/regehr/z/compiler-source/gcc/gcc/cp/typeck2.c:2108
0x741306 process_subob_fn
        /home/regehr/z/compiler-source/gcc/gcc/cp/method.c:1109
0x74353a walk_field_subobs
        /home/regehr/z/compiler-source/gcc/gcc/cp/method.c:1288
0x744042 synthesized_method_walk
        /home/regehr/z/compiler-source/gcc/gcc/cp/method.c:1527
0x748ef4 maybe_explain_implicit_delete(tree_node*)
        /home/regehr/z/compiler-source/gcc/gcc/cp/method.c:1627
0x69ef80 mark_used(tree_node*, int)
        /home/regehr/z/compiler-source/gcc/gcc/cp/decl2.c:5087
0x764a0c finish_id_expression(tree_node*, tree_node*, tree_node*, cp_id_kind*,
bool, bool, bool*, bool, bool, bool, bool, char const**, unsigned int)
        /home/regehr/z/compiler-source/gcc/gcc/cp/semantics.c:3636
0x6cf689 cp_parser_primary_expression
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:5068
0x6d0f79 cp_parser_postfix_expression
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:6447
0x6daf08 cp_parser_unary_expression
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:7688
0x6dbc58 cp_parser_binary_expression
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:8442
0x6dc51f cp_parser_assignment_expression
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:8712
0x6dc983 cp_parser_constant_expression
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:8964
0x6df1a6 cp_parser_late_parse_one_default_arg
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:25705
0x6c611d cp_parser_late_parsing_nsdmi
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:25755
0x6c611d cp_parser_class_specifier_1
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:21028
0x6c85d9 cp_parser_class_specifier
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:21081
0x6c85d9 cp_parser_type_specifier
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:15391
0x6e568b cp_parser_decl_specifier_seq
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:12343
0x6f1221 cp_parser_simple_declaration
        /home/regehr/z/compiler-source/gcc/gcc/cp/parser.c:11909
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regehr@hawking:~/svn/code/reduce/creduce_extra_698/reduce$