Bug#180937: g++ internal compiler error: Error reporting routines re-entered

[Daniel Jacobowitz <dan@debian.org>]

On Fri, Feb 14, 2003 at 12:14:01AM -0500, H. S. Teoh wrote:
> Package: g++
> Version: 3.2.2-0
> Severity: important
> 
> The attached source file causes g++ to report an internal compiler error:
> 
> % g++ -c g++bug.cc
> g++bug.cc: In function `int main(int, char**)':
> g++bug.cc:29: jump to case label
> g++bug.cc:26:   crosses initialization of `someclass obj1'
> g++bug.cc:33: jump to case label
> g++bug.cc:30:   crosses initialization of `someotherclass obj2'
> g++bug.cc:26:   crosses initialization of `someclass obj1'
> 
> Internal compiler error: Error reporting routines re-entered.
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.

An ICE is always a bug, but...

> I'm not sure what is the cause of this; it seems to be something to do
> with the switch statement and the fact that someclass and someotherclass
> have destructors. (Commenting out the destructors in those classes makes
> the internal compiler error go away, somehow.)
> 
> Also, why doesn't g++ like the declaration of objects inside a switch
> statement? Is this invalid according to the C++ spec, or is it a GCC
> oddity? Regardless, the internal compiler error is certainly a bug. 

I'm pretty sure it's illegal.  Consider this - what is the scope of
obj1 in the below?  It starts at the first label, and goes until the
end of the case block.  So it's in scope at CHOICE_B.  But its
constructor wasn't called....

>   switch (choice) {
>   case CHOICE_A:
>     someclass obj1(&commonobj);
> 
>     break;
>   case CHOICE_B:
>     someotherclass obj2(&commonobj);
> 
>     break;
>   default:
>     break;
>   }
> }

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer