[Bug libstdc++/58839] New: Regression: dereferencing void in shared_ptr(unique_ptr&& u) constructor

[mrlika at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58839

Bug ID: 58839
   Summary: Regression: dereferencing void in
shared_ptr(unique_ptr&& u) constructor
   Product: gcc
   Version: 4.8.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: libstdc++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: mrlika at gmail dot com

This completely valid C++11 code does not compile when T is void.

template 
void f() {
std::unique_ptr sp;
std::shared_ptr up(std::move(sp));
}

int main() {
f();
//f(); // Error /usr/include/c++/4.8/bits/shared_ptr_base.h:851:34:
error: ‘std::unique_ptr >::pointer {aka void*}’
is not a pointer-to-object type
}

This bug makes impossible to use shared_ptr constructor that takes unique_ptr
rvalue reference as a parameter with type of pointer T=void.

This is regression appeared after changing line in shared_ptr_base.h from

 _Tp1* __tmp = __r.get();

to

auto __tmp = std::__addressof(*__r.get());

in the following commit:

2012-11-07 paolo2012-11-07 Paolo Carlini 

[Bug libstdc++/58839] Regression: dereferencing void* in shared_ptr(unique_ptr&& u) constructor

[mrlika at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58839

--- Comment #2 from Andriy Lysnevych  ---
Hi Paolo,

You are right. It is not yours commit but next one.

__r.get() returns T* and construction *__r.get() works for any type except the
case when T=void. It causes dereferencing of void pointer that is prohibited by
standard.
When code creates unique_ptr a resource hidden behind void pointer (most
likely with custom deleter functionality) and then tries to pass it to
shared_ptr(unique_ptr&&) constructor we get this void dereferencing
error.

Regards

[Bug c++/70353] New: static_assert + assert + c++14 crashes GCC

[mrlika at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70353

Bug ID: 70353
   Summary: static_assert + assert + c++14 crashes GCC
   Product: gcc
   Version: 5.2.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: mrlika at gmail dot com
  Target Milestone: ---

I use out-of-the-box GCC 5.2.1 in Ubuntu 15.10:

gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2)

This code makes GCC crash when I define standard --std=c++14 or --std=c++17:

#include 

constexpr int ce(int r) {
  assert(r == 3);
  return r;
}

static_assert(ce(3) == 3, "static asser error");


Command to reproduce:
$ gcc --std=c++14 bug.cpp
bug.cpp:8:17:   in constexpr expansion of ‘ce(3)’
bug.cpp:8:48: internal compiler error: Segmentation fault
 static_assert(ce(3) == 3, "static asser error");
^
Please submit a full bug report,
with preprocessed source if appropriate.
See  for instructions.

[Bug c++/70353] static_assert + assert + c++14 crashes GCC

[mrlika at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70353

--- Comment #3 from Andriy Lysnevych  ---
static_assert is not required. This code also crashes:

#include 

constexpr int ce(int r) {
  assert(r == 3);
  return r;
}

const auto c = ce(3);

Problem is in assert called from constexpr function.

[Bug c++/70353] [5/6 regression] ICE on __PRETTY_FUNCTION__ in a constexpr function

[mrlika at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70353

--- Comment #8 from Andriy Lysnevych  ---
Smaller test case:

constexpr const char* ce ()
{
   return __func__;
}

const char* c = ce ();