[Bug c++/53619] New: [c++11, regression] wrong capture of "this" in lambda in case of polymorphism

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53619

             Bug #: 53619
           Summary: [c++11, regression] wrong capture of "this" in lambda
                    in case of polymorphism
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: vincenzo.innoce...@cern.ch


in this example "x" is wrongly captured
./a.out 
in foo 1
in lambda 4203472
Segmentation fault (core dumped)

removing the inheritance from B works "as expected"

It starts at the same time I had to capture "this" explicitly…
(sorry, only now had the time to debug it fully and reduce it some how)

#include<iostream>
struct CA {
  const int x;
  constexpr CA(int i) : x(i){}
};
struct B {
  virtual ~B(){}
};

struct A : public B, private CA {
  A(CA const c) : CA(c){}
  int foo(int *, int);
};


int A::foo(int * h, int l) {
  std::cout << "in foo " << x << std::endl;
  int a=0;
  auto k = [&a, &h ,this](int i) {
    std::cout << "in lambda " << x << std::endl;
    a+=h[x+i];
  };
  for (int i=0; i!=l; ++i)
     k(i);
  return a;
}



int main(int l, char **) {
  CA ca(1);
  A a(ca);
  int h[l+2]; h[0]=l;
  std::cout << a.foo(h,l) << std::endl;
}