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Re: Bug on sizeof(void) == 1, must be undefined or negative, == -100000.
- From: jc-nospam at jr-pizarro dot jazztel dot es
- To: pinskia at physics dot uc dot edu
- Cc: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 17 Jun 2005 23:27:54 +0200 (CEST)
- Subject: Re: Bug on sizeof(void) == 1, must be undefined or negative, == -100000.
On Jun 17, 2005, at 17:05:37, pinskia@physics.uc.edu wrote:
> This is invalid code and a GNU extension to take the sizeof(void). The
> reason
> why GCC defines it as 1 is because you can do the following:
> void *a;
> a++;
>
> If you want to error out on GNU extensions, use -pedantic-errors.
>
> Thanks,
> Andrew Pinski
To imagine the worst situation:
char *x = (char *)0xBAD0DAD0;
x++; // -> x = 0xBAD0DAD1 (adding +1)
int *y = x; // -> y = 0xBAD0DAD1
y++; // -> y = 0xBAD0DAD5 (adding +4, sizeof(int)==4 )
void *z = y; // -> z = 0xBAD0DAD5
z++; // adding +0? adding +1? adding +4? abort this error?
Sincerely yours, J.C.