https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85209
Bug ID: 85209
Summary: [8 Regression] ICE with lambda and structured binding
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Keywords: ice-on-invalid-code
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: reichelt at gcc dot gnu.org
Target Milestone: ---
The following invalid code snippet (compiled with "-std=c++17") triggers
an ICE on trunk:
===========================
template<int> void foo()
{
auto [a] = []{};
};
void bar()
{
foo<0>();
}
===========================
bug.cc: In instantiation of 'void foo() [with int <anonymous> = 0]':
bug.cc:8:10: required from here
bug.cc:3:8: internal compiler error: in tsubst_decomp_names, at cp/pt.c:16223
auto [a] = []{};
^~~
0x6456bb tsubst_decomp_names
../../gcc/gcc/cp/pt.c:16223
0x974695 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../gcc/gcc/cp/pt.c:16403
0x971764 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../gcc/gcc/cp/pt.c:16264
0x96f15f tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../gcc/gcc/cp/pt.c:16561
0x96e2f8 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../gcc/gcc/cp/pt.c:16249
0x96e2f8 instantiate_decl(tree_node*, bool, bool)
../../gcc/gcc/cp/pt.c:23659
0x9932db instantiate_pending_templates(int)
../../gcc/gcc/cp/pt.c:23775
0x8b893b c_parse_final_cleanups()
../../gcc/gcc/cp/decl2.c:4724
Please submit a full bug report, [etc.]
The regression was introduced between 2017-08-19 and 2017-09-02.
Before, the code was correctly rejected:
bug.cc: In instantiation of 'void foo() [with int <anonymous> = 0]':
bug.cc:8:10: required from here
bug.cc:3:8: error: cannot decompose lambda closure type 'foo() [with int
<anonymous> = 0]::<lambda()>'
auto [a] = []{};
^~~
