Re: Tasks (exception round-up)

[Phil Muldoon <pmuldoon at redhat dot com>]

Tom Tromey wrote:
> Take a look at the appended program, which is a modification to the
> one you posted.
>
>   

Yeah thank, for the pointers. I took the modified simple program and 
made it simpler.  Attached:

simplest_next_fail.cxx - really simple throw catch in main
simple_next_fail.cxx - same as simplest_next_fail but with a few extra 
frames to show next/finish driving through all of them and not returning 
control.

Basically then, this can be rendered down to: if you enact a finish or a 
next at the location of a throw statement, control of the inferior is 
lost until another breakpoint or signal is delivered. I did some 
preliminary testing with:

LD_POINTER_GUARD=0

that was mentioned in Pedro's email, but nothing good to report there so 
far. I'll spend the rest of the day stepping through next_command() and 
step_1() -> set_longjmp_breakpoint() -> create_longjmp_breakpoint 
("longjmp") code, and examine the precise sequence of events.

Regards

Phil
#include <iostream>

using namespace std;

int func1() 
{
  // break somewhere and step here.
  // Run next or finish from here. 
  // Control of the inferior should be regained
  // in the catch (...) in main.
  throw 20;
}

int main () {
  try 
    {
      func1();
    }
  catch (...) 
    {
      // Catch the throw in func1. next or finish should return
      // control here.
      cout << "Should regain control of inferior here." << endl;
    }

  // But it doesn't, it keeps on going ....
  cout << "Exiting the program." << endl;
  return 0;
}

#include <iostream>

using namespace std;

int func1() 
{
  // break somewhere and step here.
  // Run next or finish from here. 
  // Control of the inferior should be regained
  // in the catch (...) in main.
  throw 20;
}

int func2() 
{
  func1();
}

int print_exit_message() 
{
  cout << "Exiting the program." << endl;
}

int main () {
  try 
    {
      func2();
    }
  catch (...) 
    {
      // Catch the throw in func1. next or finish should return
      // control here.
      cout << "Should regain control of inferior here." << endl;
    }

  // But it doesn't, it keeps on going ....
  print_exit_message();
  return 0;
}