[Bug c++/77376] New: GCC segfaults/returns bogus error (depending on version) when calling a member function from a generic lambda with a captured this without using "this->" explicitly.

[tinab at hush dot ai]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77376

            Bug ID: 77376
           Summary: GCC segfaults/returns bogus error (depending on
                    version) when calling a member function from a generic
                    lambda with a captured this without using "this->"
                    explicitly.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tinab at hush dot ai
  Target Milestone: ---

GCC segfaults/returns bogus error (depending on version) when calling a member
function from a generic lambda with a captured this without using "this->"
explicitly.

Seems to affect all versions of GCC with different results.

On 5.4.0 a bogus error is returned: 
    error: cannot call member function ‘...’ without object

On other versions of GCC a segmentation fault occurs (up to and including GCC
7.0.0). This bug only occurs when a member function is called without "this->"
being specified from the generic lambda, using "this->" explicitly resolves the
problem.

Example (from http://coliru.stacked-crooked.com/a/2a41c21343437d9c)
===================================================================
    g++ -std=c++14 -O2 -Wall -pedantic -pthread main.cpp && ./a.out
    main.cpp: In lambda function:
    main.cpp:13:10: internal compiler error: Segmentation fault
             thing(asdf, foo);

Test case
=========

#include <iostream>
#include <string>
#include <vector>

struct Foo {
  void test();
  void thing(void* a1, std::string a2);
};

void Foo::test() {
    auto foo = "gfdgfd";
    auto l = [&](auto asdf) {
         thing(asdf, foo);
    };
    l(nullptr);
}

void Foo::thing(void* a1, std::string a2) {
}

int main()
{
}