Re: c/10719: invalid code generated (x86, "int $5") with __builtin_va_arg(va, char);

[sbiallas@online-club.de]

The following reply was made to PR c/10719; it has been noted by GNATS.

From: sbiallas@online-club.de
To: rth@gcc.gnu.org, gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org,
  nobody@gcc.gnu.org, sb@biallas.net, gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: c/10719: invalid code generated (x86, "int $5") with __builtin_va_arg(va, char);
Date: Mon, 12 May 2003 15:46:55 +0200 (MEST)

 >Not a bug.  This is in fact a feature.  As you
 note, the code
 >is bad and you should use "int".  There is no
 sensible code
 >that could be generated.
 
 I can't agree with this: gcc shouldn't generate
 invalid code on purpose. It knows there is an
 error and should generate an error and not a
 warning. The warning is misleading (it sounds like
 gcc found a problem and corrected it) and will
 probably not recognized.
 
 With the same attitude you could easily allow
 instantiating a class with abstract functions and
 segv when an abstract function is called.
 
 Additionally "int $5" is a very bad way of
 indicating bad code. This would for example
 trigger a "print screen" on DOS or could even be a
 syscall on other systems.
 
 Regards,
 Sebastian