[Bug c++/111728] New: C++ 20 coroutine segmentation fault in generic lambda

[Bug c++/111728] New: C++ 20 coroutine segmentation fault in generic lambda

[yunus at ayar dot eu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111728

            Bug ID: 111728
           Summary: C++ 20 coroutine segmentation fault in generic lambda
           Product: gcc
           Version: 13.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: yunus at ayar dot eu
  Target Milestone: ---

Created attachment 56074
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56074&action=edit
Compressed version of main.cpp.ii (~ 5.5 MB) from g++ -save-temps

The following code causes a segmentation fault with ASIO 1.28, C++ 20's
coroutines and evaluating of expressions inside a generic coroutine lambda. I
tried to strip the test case as much as possible:

```cpp
#include <asio.hpp>
#include <cstddef>

inline asio::awaitable<std::size_t> write_fields()
{
  std::byte static_buffer[10];

  co_await [&](auto field) -> asio::awaitable<int> {
    // Next line is not ok.
    if (0 == sizeof(static_buffer));
    co_return 0;
  }(0);

  co_return 0;
}

int main() { static_cast<void>(write_fields()); }
```


My exact version:

```txt
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/13/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,fortran,objc,obj-c++,ada,go,d,m2,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-gcc-major-version-only --enable-libstdcxx-backtrace
--with-libstdcxx-zoneinfo=/usr/share/zoneinfo --with-linker-hash-style=gnu
--enable-plugin --enable-initfini-array
--with-isl=/builddir/build/BUILD/gcc-13.2.1-20230728/obj-x86_64-redhat-linux/isl-install
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-offload-defaulted --enable-gnu-indirect-function --enable-cet
--with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
--with-build-config=bootstrap-lto --enable-link-serialization=1
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.2.1 20230728 (Red Hat 13.2.1-1) (GCC)
```


I compiled the attached (main.cpp.ii) with: g++ main.cpp.ii -std=gnu++20
The following output was generated:

```txt
/home/yunus/Projects/terraqtt/examples/main.cpp: In instantiation of
‘write_fields(write_fields()::_Z12write_fieldsv.Frame*)::<lambda(auto:50)>
[with auto:50 = int]’:
/home/yunus/Projects/terraqtt/examples/main.cpp:12:4:   required from here
/home/yunus/Projects/terraqtt/examples/main.cpp:12:3: internal compiler error:
Segmentation fault
   12 |   }(0);
      |   ^
Please submit a full bug report, with preprocessed source.
See <http://bugzilla.redhat.com/bugzilla> for instructions.
Preprocessed source stored into /tmp/cchUnOPu.out file, please attach this to
your bugreport.
```

[Bug c++/111728] C++ 20 coroutine segmentation fault in generic lambda

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111728

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
[apinski@xeond2 upstream-gcc-git]$ ~/upstream-gcc/bin/gcc main.cpp.ii 
-std=gnu++20
/home/yunus/Projects/terraqtt/examples/main.cpp: In instantiation of
‘write_fields(write_fields()::_Z12write_fieldsv.Frame*)::<lambda(auto:50)>
[with auto:50 = int]’:
/home/yunus/Projects/terraqtt/examples/main.cpp:12:4:   required from here
/home/yunus/Projects/terraqtt/examples/main.cpp:12:3: internal compiler error:
in rewrite_param_uses, at cp/coroutines.cc:3798
0x792564 rewrite_param_uses
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/coroutines.cc:3798
0x1613da4 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
        /home/apinski/src/upstream-gcc-git/gcc/gcc/tree.cc:11400
0x1613ef8 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
        /home/apinski/src/upstream-gcc-git/gcc/gcc/tree.cc:11634
0xad2426 rewrite_param_uses
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/coroutines.cc:3786
0x1613da4 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
        /home/apinski/src/upstream-gcc-git/gcc/gcc/tree.cc:11400
0xccfdcc cp_walk_subtrees(tree_node**, int*, tree_node* (*)(tree_node**, int*,
void*), void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*)
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/tree.cc:5591
0x1613e13 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
        /home/apinski/src/upstream-gcc-git/gcc/gcc/tree.cc:11424
0x1613ef8 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
        /home/apinski/src/upstream-gcc-git/gcc/gcc/tree.cc:11634
0x16144a3 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
        /home/apinski/src/upstream-gcc-git/gcc/gcc/tree.cc:11516
0xaca338 coro_rewrite_function_body
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/coroutines.cc:4205
0xacf3f5 morph_fn_to_coro(tree_node*, tree_node**, tree_node**)
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/coroutines.cc:4485
0xb24b59 finish_function(bool)
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/decl.cc:18168
0xc700a6 instantiate_body
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/pt.cc:27110
0xc81bcb instantiate_decl(tree_node*, bool, bool)
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/pt.cc:27379
0xc92d5b instantiate_pending_templates(int)
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/pt.cc:27457
0xb3b2d1 c_parse_final_cleanups()
        /home/apinski/src/upstream-gcc-git/gcc/gcc/cp/decl2.cc:5060
0xd7bfc0 c_common_parse_file()
        /home/apinski/src/upstream-gcc-git/gcc/gcc/c-family/c-opts.cc:1296
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug c++/111728] C++ 20 coroutine segmentation fault in generic lambda

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111728

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-10-08
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced to just using coroutine header file:
```
#include <coroutine>
struct promise;
struct coroutine : std::coroutine_handle<promise>
{
    using promise_type = ::promise;
    bool await_ready() { return false; }
    void await_suspend( coroutine_handle h) {}
    int await_resume() {}
};
struct promise
{
    coroutine get_return_object() { return {coroutine::from_promise(*this)}; }
    std::suspend_always initial_suspend() noexcept { return {}; }
    std::suspend_always final_suspend() noexcept { return {}; }
    void return_void() {}
    void unhandled_exception() {}
};
coroutine 
write_fields() {
  int static_buffer[10];
  co_await [](auto)
  -> coroutine 
  {
    if (sizeof(static_buffer));
      co_return;
  }(0);
}
```

Confirmed.