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Re: [Bug middle-end/33279] New: Failed to warn uninitialized stack variable
- From: "Andrew Pinski" <pinskia at gmail dot com>
- To: gcc-bugzilla at gcc dot gnu dot org
- Cc: gcc-bugs at gcc dot gnu dot org
- Date: Sun, 2 Sep 2007 06:26:02 -0700
- Subject: Re: [Bug middle-end/33279] New: Failed to warn uninitialized stack variable
- References: <bug-33279-682@http.gcc.gnu.org/bugzilla/>
On 2 Sep 2007 13:19:45 -0000, hjl at lucon dot org
<gcc-bugzilla@gcc.gnu.org> wrote:
> [hjl@gnu-26 uninit-2]$ cat x.c
> typedef int mpz_t[1];
> typedef struct iterator_stack
> {
> struct iterator_stack *prev;
> mpz_t value;
> } iterator_stack;
> iterator_stack *x;
> void bar (mpz_t);
> void
> foo ()
> {
> iterator_stack frame;
> bar (frame.value);
> x = frame.prev;
> }
> [hjl@gnu-26 uninit-2]$ make
> /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
> -B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -Wuninitialized -S x.c
Not really because this is the same as
bar (&frame.value[0]);
Where bar can do pointer tricks to get back to original struct and
then change prev, trust me, this is allowed. There is a comment in
GCC sources about this specific issue.