[Bug c++/100362] [11/12 Regression] ICE with Boost.Asio async_initiate

["mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100362

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.2
            Summary|ICE with Boost.Asio         |[11/12 Regression] ICE with
                   |async_initiate              |Boost.Asio async_initiate
                 CC|                            |ppalka at gcc dot gnu.org

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
template <typename _Tp> struct remove_cv { using type = _Tp; };
class async_result {
public:
  template <typename Initiation, typename RawCompletionToken>
  static void initiate(Initiation initiation, RawCompletionToken token) {
    initiation(token);
  }
};
template <typename CompletionToken, typename, typename Initiation>
void async_initiate(Initiation initiation, CompletionToken token) {
  async_result::initiate(initiation, token);
}
template <typename> class allocator {};
template <typename, typename _Alloc> void allocate_shared(_Alloc) { }
template <typename _Tp> void make_shared() {
  allocate_shared<_Tp>(allocator<typename remove_cv<_Tp>::type>());
}
template <typename> class Foo {};
template <typename> class Qux {
public:
  template <typename CompletionToken>
  decltype(auto) AsyncOp(CompletionToken &&);
  int a_;
};
template <typename T>
template <typename CompletionToken>
decltype(auto) Qux<T>::AsyncOp(CompletionToken &&token) {
  using SignatureType = void;
  async_initiate<CompletionToken, SignatureType>(
      [this](auto) {
        struct Grault : Foo<decltype(a_)> {};
        auto ptr{make_shared<Grault>};
      },
      token);
}
void corge() {
  Qux<int> qux;
  qux.AsyncOp([] {});
}

$ xg++-10 -c 100362.C
$ xg++-11 -c 100362.C
100362.C: In instantiation of ‘struct Qux<int>::AsyncOp<corge()::<lambda()>
>(corge()::<lambda()>&&)::<lambda(auto:1)>::Grault’:
100362.C:16:23:   required from ‘void make_shared() [with _Tp =
Qux<int>::AsyncOp<corge()::<lambda()>
>(corge()::<lambda()>&&)::<lambda(auto:1)>::Grault]’
100362.C:32:14:   required from ‘Qux<int>::AsyncOp<corge()::<lambda()>
>(corge()::<lambda()>&&)::<lambda(auto:1)> [with auto:1 = corge()::<lambda()>]’
100362.C:6:15:   required from ‘static void async_result::initiate(Initiation,
RawCompletionToken) [with Initiation = Qux<int>::AsyncOp<corge()::<lambda()>
>(corge()::<lambda()>&&)::<lambda(auto:1)>; RawCompletionToken =
corge()::<lambda()>]’
100362.C:11:25:   required from ‘void async_initiate(Initiation,
CompletionToken) [with CompletionToken = corge()::<lambda()>;
<template-parameter-1-2> = void; Initiation =
Qux<int>::AsyncOp<corge()::<lambda()>
>(corge()::<lambda()>&&)::<lambda(auto:1)>]’
100362.C:29:49:   required from ‘decltype(auto) Qux< <template-parameter-1-1>
>::AsyncOp(CompletionToken&&) [with CompletionToken = corge()::<lambda()>;
<template-parameter-1-1> = int]’
100362.C:38:14:   required from here
100362.C:30:18: internal compiler error: in lookup_template_class_1, at
cp/pt.c:10005
   30 |       [this](auto) {
      |                  ^
0xd154c5 lookup_template_class_1
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:10005
0xd16c95 lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:10244
0xd2585c tsubst_aggr_type
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:13639
0xd3227f tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:15578
0xd3221f tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:15569
0xd2d9d6 tsubst_decl
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:14583
0xd36633 tsubst_copy
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:16661
0xd4eeef tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:20821
0xd492ec tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:19719
0xd4774c tsubst_non_call_postfix_expression
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:19292
0xd4daed tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:20601
0xd4711f tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:19198
0xd2f8c2 tsubst_decl
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:14933
0xd37939 tsubst_copy
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:16796
0xd4eeef tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:20821
0xd492ec tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:19719
0xd4774c tsubst_non_call_postfix_expression
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:19292
0xd4daed tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:20601
0xd34dbb tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:16223
0xd2036e tsubst_template_arg(tree_node*, tree_node*, int, tree_node*)
        /home/mpolacek/src/gcc11/gcc/cp/pt.c:12300