[Bug c++/85558] New: ICE in make_rtl_for_nonlocal_decl when using static member of template class

[xaizek at posteo dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85558

            Bug ID: 85558
           Summary: ICE in make_rtl_for_nonlocal_decl when using static
                    member of template class
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xaizek at posteo dot net
  Target Milestone: ---

Source code to reproduce the ICE
================================

// no ICE if triggerBug is not a template
template <typename T>
struct triggerBug {
    // no ICE if order of these two lines is swapped
    friend void doInitUser(bool = triggerBug::doInit);
    static bool doInit;
};

template <class T>
bool triggerBug<T>::doInit = true;

triggerBug<int> bug;

Command line and error message
==============================

$ g++-trunk gcc-bug.cpp -c -o /dev/null
gcc-bug.cpp: In instantiation of ‘struct triggerBug<int>’:
gcc-bug.cpp:12:17:   required from here
gcc-bug.cpp:10:6: internal compiler error: in make_rtl_for_nonlocal_decl, at
cp/decl.c:6587
 bool triggerBug<T>::doInit = true;
      ^~~~~~~~~~~~~
0x702c4a make_rtl_for_nonlocal_decl
        ../../gcc/cp/decl.c:6585
0x73211c cp_finish_decl(tree_node*, tree_node*, bool, tree_node*, int)
        ../../gcc/cp/decl.c:7243
0x8638f0 instantiate_class_template_1
        ../../gcc/cp/pt.c:11174
0x8638f0 instantiate_class_template(tree_node*)
        ../../gcc/cp/pt.c:11398
0x8be552 complete_type(tree_node*)
        ../../gcc/cp/typeck.c:136
0x7071e7 start_decl_1(tree_node*, bool)
        ../../gcc/cp/decl.c:5278
0x72ce17 start_decl(cp_declarator const*, cp_decl_specifier_seq*, int,
tree_node*, tree_node*, tree_node**)
        ../../gcc/cp/decl.c:5241
0x7ed93f cp_parser_init_declarator
        ../../gcc/cp/parser.c:19620
0x7ef8d9 cp_parser_simple_declaration
        ../../gcc/cp/parser.c:13063
0x7f07d8 cp_parser_block_declaration
        ../../gcc/cp/parser.c:12875
0x7fc394 cp_parser_declaration
        ../../gcc/cp/parser.c:12772
0x7fad96 cp_parser_declaration_seq_opt
        ../../gcc/cp/parser.c:12648
0x7fb0a3 cp_parser_translation_unit
        ../../gcc/cp/parser.c:4563
0x7fb0a3 c_parse_file()
        ../../gcc/cp/parser.c:39045
0x943bc5 c_common_parse_file()
        ../../gcc/c-family/c-opts.c:1132

Compiler version
================

Same results locally on 5.5.0, 7.3.0, trunk (git:
2e7e8f549a4c4c5885e4f7f5a4271f3610b54c3a, svn: 259739), and looks like any
version since 4.4 on compiler explorer (4.1 says `incomplete type
'triggerBug<int>' used in nested name specifier`). So I'm not providing
compiler flags or system details as this probably affects pretty much anything
in use today.