Re: Compiling GCC With a C++ Compiler (g++)

[Geoffrey Keating <geoffk at apple dot com>]

On 13/10/2004, at 8:23 AM, Dave Korn wrote:

> > -----Original Message-----
> > From: Joseph S. Myers
> > Sent: 13 October 2004 15:10
>
> > Without "restrict" the only relevant undefined behavior is if
> > the object
> > is *defined* with qualified type (6.7.3#5).  This can apply
> > with static or
> > automatic storage duration declarations such as
> >
> >   struct { const char x } y = { z };
> >
> > but cannot apply to an object of allocated storage duration.
>
>   Huh?  Are you saying that in:
>
> typedef struct { const char x } AA;
>
> AA *py1, py2;
> AA y1 = { z };
>
>   py1 = malloc (sizeof *py2);
>   py2 = &y1;
>
> it is valid to say
>
>   *(char *)(&py1->x) = '?';
>
> but not valid to say
>
>   *(char *)(&py2->x) = '?';

Yes, that sounds right.

As a simpler example, given

static const int x = 3;
static int y = 4;

it is valid to say

*(int *)(const int *)&y = 4;

but not

*(int *)(const int *)&x = 4;

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