https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84578
Bug ID: 84578
Summary: [6/7/8 Regression] ICE with flexible array member and
constexpr
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Keywords: ice-on-valid-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 (valid?) code snippet triggers an ICE since GCC 6.1.0:
======================================
struct A
{
constexpr A() : i(), x() {}
int i;
char x[];
};
A a;
======================================
bug.cc:8:3: in 'constexpr' expansion of 'a.A::A()'
bug.cc:8:3: internal compiler error: in tree_to_uhwi, at tree.c:6817
A a;
^
0x78c097 tree_to_uhwi(tree_node const*)
../../gcc/gcc/tree.c:6817
0x85630b cxx_eval_vec_init_1
../../gcc/gcc/cp/constexpr.c:2891
0x8523c5 cxx_eval_vec_init
../../gcc/gcc/cp/constexpr.c:3011
0x8523c5 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4535
0x854c7d cxx_eval_store_expression
../../gcc/gcc/cp/constexpr.c:3685
0x85232f cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4248
0x8528cf cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4552
0x8513f7 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4296
0x8513f7 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4296
0x852021 cxx_eval_statement_list
../../gcc/gcc/cp/constexpr.c:3898
0x852021 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4643
0x85138d cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4647
0x852021 cxx_eval_statement_list
../../gcc/gcc/cp/constexpr.c:3898
0x852021 cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4643
0x85080f cxx_eval_call_expression
../../gcc/gcc/cp/constexpr.c:1689
0x8513ab cxx_eval_constant_expression
../../gcc/gcc/cp/constexpr.c:4170
0x8569f7 cxx_eval_outermost_constant_expr
../../gcc/gcc/cp/constexpr.c:4819
0x859988 maybe_constant_init_1
../../gcc/gcc/cp/constexpr.c:5145
0x8cceaa expand_default_init
../../gcc/gcc/cp/init.c:1901
0x8cceaa expand_aggr_init_1
../../gcc/gcc/cp/init.c:2004
Please submit a full bug report, [etc.]
The code was accepted by GCC 4.5, 4.6, 4.7, 5.
It also triggered an ICE with GCC 4.8, 4.9.
