https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86478
Bug ID: 86478
Summary: Crashed on legal code
Product: gcc
Version: 8.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: zhonghao at pku dot org.cn
Target Milestone: ---
The code is as follows:
template<class ...T>
struct X
{};
template<class ...T>
void foo(X<T, T...>... a);
void test()
{
foo(X<int, int, double>(), X<double, int, double>());
}
g++ crashes when compiling the code:
code0.cpp: In substitution of 'template<class ... T> void foo(X<T, T ...>...)
[with T = <missing>]':
code0.cpp:10:53: required from here
code0.cpp:10:53: internal compiler error: tree check: expected class
'expression', have 'type' (integer_type) in tree_operand_check, at tree.h:3633
foo(X<int, int, double>(), X<double, int, double>());
^
0x79b1a2 tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
../../code/gcc/tree.c:9377
0x65b01a expr_check(tree_node*, char const*, int, char const*)
../../code/gcc/tree.h:3304
0x65b01a tree_operand_check(tree_node*, int, char const*, int, char const*)
../../code/gcc/tree.h:3633
0x65b01a unify_pack_expansion
../../code/gcc/cp/pt.c:20777
0x990032 unify
../../code/gcc/cp/pt.c:21565
0x98edf3 unify
../../code/gcc/cp/pt.c:21762
0x98fe10 unify
../../code/gcc/cp/pt.c:21559
0x98e8a2 try_class_unification
../../code/gcc/cp/pt.c:20559
0x990925 unify
../../code/gcc/cp/pt.c:21596
0x9958a3 unify_one_argument
../../code/gcc/cp/pt.c:19793
0x996520 unify_pack_expansion
../../code/gcc/cp/pt.c:20808
0x997ab6 type_unification_real
../../code/gcc/cp/pt.c:19933
0x998ab5 fn_type_unification(tree_node*, tree_node*, tree_node*, tree_node*
const*, unsigned int, tree_node*, unification_kind_t, int, bool, bool)
../../code/gcc/cp/pt.c:19298
0x839f0f add_template_candidate_real
../../code/gcc/cp/call.c:3179
0x83a920 add_template_candidate
../../code/gcc/cp/call.c:3258
0x83a920 add_candidates
../../code/gcc/cp/call.c:5520
0x83ad31 add_candidates
../../code/gcc/cp/call.c:4192
0x83ad31 perform_overload_resolution
../../code/gcc/cp/call.c:4200
0x83cda2 build_new_function_call(tree_node*, vec<tree_node*, va_gc,
vl_embed>**, int)
../../code/gcc/cp/call.c:4273
0x9bb475 finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
../../code/gcc/cp/semantics.c:2534
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.
Clang++ accepts the above code.
