[Bug c++/79371] New: ICE on valid C++14 code on x86_64-linux-gnu: in build_class_member_access_expr, at cp/typeck.c:2296

["su at cs dot ucdavis.edu" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79371

            Bug ID: 79371
           Summary: ICE on valid C++14 code on x86_64-linux-gnu: in
                    build_class_member_access_expr, at cp/typeck.c:2296
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

This ICE seems to be a recent regression. The code is mistakenly rejected by
GCC 6.x and earlier. 

It is correctly accepted by Clang and crashes ICC. 

$ g++-trunk -v
Using built-in specs.
COLLECT_GCC=g++-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/7.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/usr/local/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 7.0.1 20170203 (experimental) [trunk revision 245148] (GCC) 
$ 
$ clang++ -c -std=c++14 small.cpp
$ icc -c -std=c++14 small.cpp
small.cpp(6): internal error: assertion failed at:
"shared/cfe/edgcpfe/class_decl.c", line 3575

  int b = S().a < int >;
          ^

compilation aborted for small.cpp (code 4)
$ 
$ g++-trunk -c -std=c++14 small.cpp
small.cpp:6:13: internal compiler error: in build_class_member_access_expr, at
cp/typeck.c:2296
 int b = S().a < int >;
             ^~~~~~~~~
0x80a0cc build_class_member_access_expr(cp_expr, tree_node*, tree_node*, bool,
int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:2296
0x80a48a finish_class_member_access_expr(cp_expr, tree_node*, bool, int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:2900
0x7c47b4 cp_parser_postfix_dot_deref_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:7443
0x7c1d44 cp_parser_postfix_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:7046
0x7bdcbc cp_parser_unary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8098
0x7caa17 cp_parser_cast_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8775
0x7caff3 cp_parser_binary_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:8876
0x7cb8e4 cp_parser_assignment_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9163
0x7cbd2a cp_parser_constant_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9433
0x7cc584 cp_parser_initializer_clause
        ../../gcc-source-trunk/gcc/cp/parser.c:21569
0x7ce093 cp_parser_initializer
        ../../gcc-source-trunk/gcc/cp/parser.c:21509
0x7ddf80 cp_parser_init_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:19328
0x7de7e1 cp_parser_simple_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12776
0x7df52a cp_parser_block_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12594
0x7e77f4 cp_parser_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12491
0x7e7b66 cp_parser_declaration_seq_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:12367
0x7e7e84 cp_parser_translation_unit
        ../../gcc-source-trunk/gcc/cp/parser.c:4366
0x7e7e84 c_parse_file()
        ../../gcc-source-trunk/gcc/cp/parser.c:38382
0x94d6f2 c_common_parse_file()
        ../../gcc-source-trunk/gcc/c-family/c-opts.c:1107
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.
$ 


--------------------------------------------


struct S
{
  template < typename > static int &a;
};

int b = S().a < int >;