https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84822
Bug ID: 84822
Summary: Partial specializing template<auto> internal compiler
error
Product: gcc
Version: 7.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: feiteng at gmail dot com
Target Milestone: ---
Created attachment 43625
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43625&action=edit
the preprocessed file (*.i*) that triggers the bug
When partially specializing template<auto> with more than one auto non-type
template parameters, a mixed usage of auto non-type template argument and named
non-type template argument causes ICE.
Example code
https://godbolt.org/g/3GebP8
contains several variants of the error.
g++ (Ubuntu 7.2.0-1ubuntu1~16.04) 7.2.0
g++ partialspecializationbug.cpp -std=c++17
partialspecializationbug.cpp:72:34: internal compiler error: Segmentation fault
Listener<&Foo::evt, &Bar::f> conn;
^~~~
0xae558f crash_signal
../../src/gcc/toplev.c:337
0x5e187a unify
../../src/gcc/cp/pt.c:20513
0x5e1680 unify
../../src/gcc/cp/pt.c:21006
0x5f36e1 unify_one_argument
../../src/gcc/cp/pt.c:19128
0x5f8726 type_unification_real
../../src/gcc/cp/pt.c:19248
0x5e0313 do_auto_deduction(tree_node*, tree_node*, tree_node*, int,
auto_deduction_context, tree_node*, int)
../../src/gcc/cp/pt.c:25537
0x5e1f5d unify
../../src/gcc/cp/pt.c:20662
0x5e1508 unify
../../src/gcc/cp/pt.c:20851
0x5e2991 get_partial_spec_bindings
../../src/gcc/cp/pt.c:21648
0x5e2d1d most_specialized_partial_spec
../../src/gcc/cp/pt.c:21919
0x5fe4db instantiate_class_template_1
../../src/gcc/cp/pt.c:10312
0x5fe4db instantiate_class_template(tree_node*)
../../src/gcc/cp/pt.c:10880
0x662305 complete_type(tree_node*)
../../src/gcc/cp/typeck.c:133
0x5cea01 grokdeclarator(cp_declarator const*, cp_decl_specifier_seq*,
decl_context, int, tree_node**)
../../src/gcc/cp/decl.c:12043
0x61e302 grokfield(cp_declarator const*, cp_decl_specifier_seq*, tree_node*,
bool, tree_node*, tree_node*)
../../src/gcc/cp/decl2.c:806
0x63343b cp_parser_member_declaration
../../src/gcc/cp/parser.c:23419
0x633e0a cp_parser_member_specification_opt
../../src/gcc/cp/parser.c:22968
0x633e0a cp_parser_class_specifier_1
../../src/gcc/cp/parser.c:22121
0x635a61 cp_parser_class_specifier
../../src/gcc/cp/parser.c:22373
0x635a61 cp_parser_type_specifier
../../src/gcc/cp/parser.c:16446
