Strange seg fault error

Question

I'm getting a strange segfault error. I've pasted the relevant parts of the code below.

When I run the code in gdb I get the following output:

DERPE
DERPH0 1

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00007fff5f3ffff0
0x000000010000fcee in Interval::contains (this=0x100103c90, other={isValid = 93, s = 1, e = 7, n = 5}) at interval.cpp:33
33      if (!contains(other.s)) {

A.cpp

void A::foo(){
    ...
    std::cout << "DERPE" << std::endl;
    std::cout << "DERPH" << id << " " << curr << std::endl;
    \\graph is a vector<B>
    std::cout << "DERPI" << id << " " << curr << " " << graph[id].bar(graph[curr]) << std::endl;
    ...
}

B.cpp

bool B::bar(B &other) const {
    // each B contains 2 Intervals, adj, opp
    return (other.adj.contains(this->adj) and 
           (!this->opp.isValid or other.adj.contains(this->opp) or   
           (other.opp.isValid and other.opp.contains(this->opp))));
}

Interval.cpp

bool Interval::contains(Interval other) const {
    if (!contains(other.s)) {
    return false;
    }
    ...
}

When I try to mess around with gdb I get the following:

(gdb) p other
$1 = {
  isValid = 93,
  s = 1,
  e = 7,
  n = 5
}
(gdb) p this
$2 = (const Interval *) 0x100103c90
(gdb) p *this
$3 = {
  isValid = 93,
  s = 1,
  e = 0,
  n = 5
}
(gdb) p other.s
$4 = 1
(gdb) p (*this).contains(other.s)

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00007fff5f3fff50
Interval::contains (this=Cannot access memory at address 0x7fff5f3fff50
) at interval.cpp:28
28  bool Interval::contains(int x) const {
The program being debugged was signaled while in a function called from GDB.
GDB remains in the frame where the signal was received.
To change this behavior use "set unwindonsignal on"
Evaluation of the expression containing the function (Interval::contains(int) const) will be abandoned.
(gdb) p this
Cannot access memory at address 0x7fff5f3fff50

Any ideas on how to approach this? I'm lost.

EDIT: The full header file for Interval is as follows:

Interval.h

#ifndef INTERVAL_H
#define INTERVAL_H

#include <vector>

    struct Interval {
        bool isValid;
        int s, e, n;

        Interval() {};
        Interval(int n);
        Interval(int start, int end, int n);
        bool operator==(const Interval other) const;
        int length() const;
        bool contains(int x) const;
        bool contains(Interval other) const;
    };
#endif

I don't have a copy constructor, but I figured that everything is just primitives, so the default copy constructor would work.

I played around with it some more and this seems relevant:

(gdb) backtrace 10
#0  0x000000010000fcce in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:33
#1  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#2  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#3  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#4  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#5  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#6  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#7  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#8  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
#9  0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52    
(gdb) backtrace
#0  0x000000010000fcce in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:33
...
#67667 0x000000010000fd9b in Interval::contains (this=0x100103c90, other={isValid = 34, s = 1, e = 6, n = 5}) at interval.cpp:52
(gdb)

Answer 1

I figured it out. Infinite backtrace meant that the recursion in contains was not handled properly (I was missing a base case), so it infinitely recursed -> stack overflow -> seg fault.