[Bug c++/88216] New: ICE (-std=c++2a) in cxx_eval_constant_expression, at cp/constexpr.c:4602

[emmanuel.le-trong@cnrs-orleans.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88216

            Bug ID: 88216
           Summary: ICE (-std=c++2a) in cxx_eval_constant_expression, at
                    cp/constexpr.c:4602
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: emmanuel.le-trong@cnrs-orleans.fr
  Target Milestone: ---

$ g++-9 -v                                                                      
Using built-in specs.
COLLECT_GCC=g++-9
COLLECT_LTO_WRAPPER=/home/manu/system/opt/gcc-9/libexec/gcc/x86_64-pc-linux-gnu/9.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-9/configure --prefix=/home/manu/system/opt/gcc-9
--program-suffix=-9
Thread model: posix
gcc version 9.0.0 20181123 (experimental) (GCC) 

$ cat bug.cpp                                                                   
    struct 
T {};

    template <T t>
    struct 
U {};

    template <T t>
    int
f (U <t>);


$ g++-9 -std=c++2a -Wall -Wextra -c bug.cpp                                     
bug.cpp:10:8: internal compiler error: in cxx_eval_constant_expression, at
cp/constexpr.c:4602
   10 | f (U <t>);
      |        ^
0x5ee04a cxx_eval_constant_expression
        ../../gcc-9/gcc/cp/constexpr.c:4602
0x8759b6 cxx_eval_call_expression
        ../../gcc-9/gcc/cp/constexpr.c:1511
0x877af8 cxx_eval_constant_expression
        ../../gcc-9/gcc/cp/constexpr.c:4296
0x87cf3e cxx_eval_outermost_constant_expr
        ../../gcc-9/gcc/cp/constexpr.c:5032
0x9a9f03 get_template_parm_object
        ../../gcc-9/gcc/cp/pt.c:6665
0x9a9f03 convert_nontype_argument
        ../../gcc-9/gcc/cp/pt.c:7126
0x9a9f03 convert_template_argument
        ../../gcc-9/gcc/cp/pt.c:8033
0x9a9f03 convert_template_argument
        ../../gcc-9/gcc/cp/pt.c:7784
0x995793 coerce_template_parms
        ../../gcc-9/gcc/cp/pt.c:8509
0x9a115e lookup_template_class_1
        ../../gcc-9/gcc/cp/pt.c:9325
0x9a115e lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
        ../../gcc-9/gcc/cp/pt.c:9684
0x9d29db finish_template_type(tree_node*, tree_node*, int)
        ../../gcc-9/gcc/cp/semantics.c:3247
0x950295 cp_parser_template_id
        ../../gcc-9/gcc/cp/parser.c:16295
0x950406 cp_parser_class_name
        ../../gcc-9/gcc/cp/parser.c:22858
0x95376b cp_parser_qualifying_entity
        ../../gcc-9/gcc/cp/parser.c:6644
0x95376b cp_parser_nested_name_specifier_opt
        ../../gcc-9/gcc/cp/parser.c:6330
0x950b78 cp_parser_simple_type_specifier
        ../../gcc-9/gcc/cp/parser.c:17634
0x947be5 cp_parser_type_specifier
        ../../gcc-9/gcc/cp/parser.c:17307
0x948a8e cp_parser_decl_specifier_seq
        ../../gcc-9/gcc/cp/parser.c:13961
0x9618b0 cp_parser_parameter_declaration
        ../../gcc-9/gcc/cp/parser.c:21973
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.