Fix stdlib/tst-setcontext.c for GCC 12 -Warray-compare

Message ID alpine.DEB.2.22.394.2110041842230.3528554@digraph.polyomino.org.uk
State Committed
Commit a0f0c08e4fe18e78866539b0571f8e4b57dba7a3
Headers
Series Fix stdlib/tst-setcontext.c for GCC 12 -Warray-compare |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

Joseph Myers Oct. 4, 2021, 6:42 p.m. UTC
  Building stdlib/tst-setcontext.c fails with GCC mainline:

tst-setcontext.c: In function 'f2':
tst-setcontext.c:61:16: error: comparison between two arrays [-Werror=array-compare]
   61 |   if (on_stack < st2 || on_stack >= st2 + sizeof (st2))
      |                ^
tst-setcontext.c:61:16: note: use '&on_stack[0] < &st2[0]' to compare the addresses

The comparison in this case is deliberate, so adjust it as suggested
in that note.

Tested with build-many-glibcs.py (GCC mainline) for aarch64-linux-gnu.
  

Comments

Adhemerval Zanella Oct. 5, 2021, 11:35 a.m. UTC | #1
On 04/10/2021 15:42, Joseph Myers wrote:
> Building stdlib/tst-setcontext.c fails with GCC mainline:
> 
> tst-setcontext.c: In function 'f2':
> tst-setcontext.c:61:16: error: comparison between two arrays [-Werror=array-compare]
>    61 |   if (on_stack < st2 || on_stack >= st2 + sizeof (st2))
>       |                ^
> tst-setcontext.c:61:16: note: use '&on_stack[0] < &st2[0]' to compare the addresses
> 
> The comparison in this case is deliberate, so adjust it as suggested
> in that note.
> 
> Tested with build-many-glibcs.py (GCC mainline) for aarch64-linux-gnu.
> 


LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> diff --git a/stdlib/tst-setcontext.c b/stdlib/tst-setcontext.c
> index 1b511708c1..1c2925bb76 100644
> --- a/stdlib/tst-setcontext.c
> +++ b/stdlib/tst-setcontext.c
> @@ -58,7 +58,7 @@ f2 (void)
>    puts ("start f2");
>  
>    printf ("&on_stack=%p\n", on_stack);
> -  if (on_stack < st2 || on_stack >= st2 + sizeof (st2))
> +  if (&on_stack[0] < &st2[0] || &on_stack[0] >= st2 + sizeof (st2))
>      {
>        printf ("%s: memory stack is not where it belongs!", __FUNCTION__);
>        exit (1);
>
  

Patch

diff --git a/stdlib/tst-setcontext.c b/stdlib/tst-setcontext.c
index 1b511708c1..1c2925bb76 100644
--- a/stdlib/tst-setcontext.c
+++ b/stdlib/tst-setcontext.c
@@ -58,7 +58,7 @@  f2 (void)
   puts ("start f2");
 
   printf ("&on_stack=%p\n", on_stack);
-  if (on_stack < st2 || on_stack >= st2 + sizeof (st2))
+  if (&on_stack[0] < &st2[0] || &on_stack[0] >= st2 + sizeof (st2))
     {
       printf ("%s: memory stack is not where it belongs!", __FUNCTION__);
       exit (1);