[Bug c++/85027] New: ICE on invalid C++ code: in instantiate_type, at cp/class.c:8062

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85027

            Bug ID: 85027
           Summary: ICE on invalid C++ code: in instantiate_type, at
                    cp/class.c:8062
           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: ---

It seems to affect all versions since at least as early as 4.x. 

$ g++tk -v
Using built-in specs.
COLLECT_GCC=g++tk
COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 8.0.1 20180321 (experimental) [trunk revision 258722] (GCC)
$
$ g++tk tmp.cpp
tmp.cpp:3:18: internal compiler error: in instantiate_type, at cp/class.c:8062
 int t = A::A ? : 0;
                  ^
0x6f4360 instantiate_type(tree_node*, tree_node*, int)
        ../../gcc-source-trunk/gcc/cp/class.c:8062
0x6cffea perform_implicit_conversion_flags(tree_node*, tree_node*, int, int)
        ../../gcc-source-trunk/gcc/cp/call.c:10628
0x6dfc83 build_conditional_expr_1
        ../../gcc-source-trunk/gcc/cp/call.c:4962
0x6e1b2c build_conditional_expr(unsigned int, tree_node*, tree_node*,
tree_node*, int)
        ../../gcc-source-trunk/gcc/cp/call.c:5399
0x90b513 build_x_conditional_expr(unsigned int, tree_node*, tree_node*,
tree_node*, int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:6565
0x810ee3 cp_parser_question_colon_clause
        ../../gcc-source-trunk/gcc/cp/parser.c:9456
0x8100c6 cp_parser_assignment_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9492
0x8110b3 cp_parser_constant_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9770
0x8115d7 cp_parser_initializer_clause
        ../../gcc-source-trunk/gcc/cp/parser.c:21928
0x8147cb cp_parser_initializer
        ../../gcc-source-trunk/gcc/cp/parser.c:21868
0x8385d3 cp_parser_init_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:19677
0x83a1bf cp_parser_simple_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:13065
0x83b108 cp_parser_block_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12883
0x847034 cp_parser_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12780
0x8459b6 cp_parser_declaration_seq_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:12656
0x845cd3 cp_parser_translation_unit
        ../../gcc-source-trunk/gcc/cp/parser.c:4561
0x845cd3 c_parse_file()
        ../../gcc-source-trunk/gcc/cp/parser.c:39017
0x98fe15 c_common_parse_file()
        ../../gcc-source-trunk/gcc/c-family/c-opts.c:1132
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.
$


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


struct A { static int a; };

// should have been: 
// int t = A::a ? : 0;
int t = A::A ? : 0;