https://issues.dlang.org/show_bug.cgi?id=21694

RazvanN <razvan.nitu1305@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |razvan.nitu1305@gmail.com

--- Comment #1 from RazvanN <razvan.nitu1305@gmail.com> ---
Actually, the goto is not legal because it skips the declaration of b. For example, this does not compile:

struct A { /*~this() {}*/ }

void test(int x)
{
   {
      A a;
      goto END;
   }
   A b;

END:

}

onlineapp.d(7): Error: goto skips declaration of variable onlineapp.test.b at
onlineapp.d(9)

Commenting b makes the code compile both with and without the destructor. It seems that the error message somehow gets swallowed.

--

https://issues.dlang.org/show_bug.cgi?id=21694

--- Comment #2 from Răzvan Ștefănescu <rumbu@rumbu.ro> ---
The error message is not swallowed because the code is lowered in a 'try {goto} finally', therefore there is no b declaration to jump over in the same scope as goto after lowering.

If you replace the goto with a simple return, it is allowed. Skipping b declaration is perfectly legit as long as b destructor is skipped, that's how the return instruction will be lowered:

void test(int x)
{
        A a = 0;
        try
        {
           return;
        }
        finally
          a.~this();
        A b = 0;
        b.~this();
}


The problem is that the original code is lowered to:

void test(int x)
{
        A a = 0;
        try
        {
           goto END;
        }
        finally
          a.~this();
        A b = 0;
        END:
        b.~this();
}

instead of the correct lowering:

void test(int x)
{
        A a = 0;
        try
        {
           goto END;
        }
        finally
          a.~this();
        A b = 0;
        b.~this();
        END:
}


By the way, the C++ compiler (MSVC) lowers the same code like this, which is
fine:


void test(int x)
{
   {
     A a = {};
     ~a;
     goto END:
   }
   A b = {};
   ~b;
END:;
}

--

https://issues.dlang.org/show_bug.cgi?id=21694

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P1                          |P2

--

https://issues.dlang.org/show_bug.cgi?id=21694

Nick Treleaven <nick@geany.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nick@geany.org

--- Comment #3 from Nick Treleaven <nick@geany.org> ---
run.dlang.io gives:

2.075.1 to 2.087.1: Failure with output: onlineapp.d(7): Error: `goto` skips
declaration of variable `onlineapp.test.b` at onlineapp.d(9)
Since      2.088.1: Failure with output: onlineapp.d(7): Error: cannot `goto`
into `try` block

Possibly related to Issue 20096: https://github.com/dlang/dmd/pull/10266

--