https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87523
Bug ID: 87523
Summary: ICE: Closures apparently fail to capture constexpr
Product: gcc
Version: 7.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: williamtnavarre at mail dot com
Target Milestone: ---
Possibly related to PR 86429?
It's not exactly the same because in this test case there is a failure even
though I'm not even demanding that the compiler necessarily consider the the
captured variable constexpr.
This is the full file below. No #include is required to observe the failing
behavior.
From g++ --version: g++ (Ubuntu 7.3.0-27ubuntu1~18.04) 7.3.0
Command: g++ -std=c++17 inp.cpp
===
template <typename T, T v>
struct my_integer_constant {
constexpr my_integer_constant() {}
constexpr operator T() const { return v; }
constexpr T operator()() const { return v; }
};
template <typename T, T... u>
struct constant_call {
template <typename Callback>
static void call(T v, Callback f) {
char dummy[sizeof...(u)] = { ( (v == u) ? (f(my_integer_constant<T,
u>{}), static_cast<char>(0)) : static_cast<char>(0))... };
(void)dummy;
}
};
void f(bool reverse_in, bool other_bool_in) {
auto helper = [&] (auto reverse_t) {
bool constexpr reverse_v = reverse_t;
(void)reverse_v;
constant_call<bool, true, false>::call(other_bool_in,
[&] (auto newb) {
bool reverse_v_dyn =
reverse_v;
});
};
constant_call<bool, true, false>::call(reverse_in, [&] (auto reverse_t) {
helper(reverse_t);
});
}
===
Output includes:
./table/src/inp.cpp:23:57: internal compiler error: in tsubst_copy, at
cp/pt.c:14588
bool reverse_v_dyn =
reverse_v;
^~~~~~~~~~~~~
