[Bug c++/71827] New: ICE on invalid C++11 code with illegal non-type template argument: in convert_nontype_argument, at cp/pt.c:6014

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71827

            Bug ID: 71827
           Summary: ICE on invalid C++11 code with illegal non-type
                    template argument: in convert_nontype_argument, at
                    cp/pt.c:6014
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

The following C++11 code causes an ICE when compiled with the current GCC trunk
on x86_64-linux-gnu in both 32-bit and 64-bit modes.  

It seems to affect all versions since as early as 4.7.x (when C++11 started to
be supported). 


$ 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/7.0.0/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 7.0.0 20160709 (experimental) [trunk revision 238191] (GCC) 
$ 
$ g++-trunk -c small.cpp
small.cpp: In function ‘void foo()’:
small.cpp:5:41: internal compiler error: in convert_nontype_argument, at
cp/pt.c:6418
  m: n: A < int, (long) &&n - (long) &&m > a;
                                         ^
0x6e8707 convert_nontype_argument
        ../../gcc-source-trunk/gcc/cp/pt.c:6418
0x6ef463 convert_template_argument
        ../../gcc-source-trunk/gcc/cp/pt.c:7287
0x6faa8b coerce_template_parms
        ../../gcc-source-trunk/gcc/cp/pt.c:7748
0x6fd7ea lookup_template_class_1
        ../../gcc-source-trunk/gcc/cp/pt.c:8331
0x6fd7ea lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
        ../../gcc-source-trunk/gcc/cp/pt.c:8672
0x81769d finish_template_type(tree_node*, tree_node*, int)
        ../../gcc-source-trunk/gcc/cp/semantics.c:3133
0x7a3ce4 cp_parser_template_id
        ../../gcc-source-trunk/gcc/cp/parser.c:14919
0x7a3f8a cp_parser_class_name
        ../../gcc-source-trunk/gcc/cp/parser.c:21223
0x7929ad cp_parser_qualifying_entity
        ../../gcc-source-trunk/gcc/cp/parser.c:6250
0x7929ad cp_parser_nested_name_specifier_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:5934
0x7b0ead cp_parser_simple_type_specifier
        ../../gcc-source-trunk/gcc/cp/parser.c:16242
0x789c81 cp_parser_type_specifier
        ../../gcc-source-trunk/gcc/cp/parser.c:15919
0x7a4673 cp_parser_decl_specifier_seq
        ../../gcc-source-trunk/gcc/cp/parser.c:12763
0x7adc91 cp_parser_simple_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12304
0x7ae0e1 cp_parser_block_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12251
0x7aeb38 cp_parser_declaration_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:11863
0x78d01b cp_parser_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:10531
0x78d93c cp_parser_statement_seq_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:10809
0x78da2f cp_parser_compound_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:10763
0x7ac2cf cp_parser_function_body
        ../../gcc-source-trunk/gcc/cp/parser.c:20701
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.
$ 


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


template < typename T, T > struct A {};

void foo () 
{
 m: n: A < int, (long) &&n - (long) &&m > a;
}