warning not issued

warning not issued

[Tudor Hulubei]

Hi,

The following code does not warn you that the initialization of `t' is
skipped.  The result is a segfault when exiting main.  I'm using
egcs-1.1b on RedHat 5.1.

#include <vector>

int
main(int argc)
{
    goto done;
    vector<int> t;
  done:;
}

Regards,
Tudor

Re: warning not issued

[Joe Buck]

> The following code does not warn you that the initialization of `t' is
> skipped.  The result is a segfault when exiting main.

This is not legal C++; you can't jump around an initializer with a
goto or a switch unless the initializer is inside curly braces.
Just the same, the compiler should have caught it ... I'm sure this
was missed because most folks don't use goto.

> egcs-1.1b on RedHat 5.1.
> 
> #include <vector>
> 
> int
> main(int argc)
> {
>     goto done;
>     vector<int> t;
>   done:;
> }

Re: warning not issued

[Martin von Loewis]

> This is not legal C++; you can't jump around an initializer with a
> goto or a switch unless the initializer is inside curly braces.
> Just the same, the compiler should have caught it ... I'm sure this
> was missed because most folks don't use goto.

I think this is exactly the complaint. The compiler does catch cases
like

struct X{
  X();
};


main()
{
  goto a;
  X x;
  a: X y;
}

Bug reports should go to egcs-bugs@cygnus.com, though.

Regards,
Martin

Re: warning not issued

[Alexandre Oliva]

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Tudor Hulubei <tudor@cs.unh.edu> writes:

> The following code does not warn you that the initialization of `t' is
> skipped.

Thanks for your report, I installed the attached testcase to the
testsuite.

-- 
Alexandre Oliva
mailto:oliva@dcc.unicamp.br mailto:oliva@gnu.org mailto:aoliva@acm.org
http://www.dcc.unicamp.br/~oliva
Universidade Estadual de Campinas, SP, Brasil

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// Build don't link:

// Based on a testcase submitted by Tudor Hulubei <tudor@cs.unh.edu>

// X is not a POD because it has a user-defined destructor.
// Therefore, we can't cross its initialization.

// vector<int> is not even an aggregate; nevertheless, no error is
// reported...

struct A {
  A() {}
};

void a() {
  goto bar; // ERROR - jump from here
  A x; // ERROR - jump crosses initialization
 bar: // ERROR - jump to here
  ;
}

struct X {
  ~X() {}
};

void b() {
  goto bar; // ERROR - jump from here - XFAIL *-*-*
  X x; // ERROR - jump crosses initialization - XFAIL *-*-*
 bar: // ERROR - jump to here - XFAIL *-*-*
  ;
}

#include <vector>

void c() {
  goto bar; // ERROR - jump from here - XFAIL *-*-*
  vector<int> x; // ERROR - jump crosses initialization - XFAIL *-*-*
 bar: // ERROR - jump to here - XFAIL *-*-*
  ;
}