[Bug tree-optimization/84315] missing -Wnonnull for trivial null pointer dereference

["egallager at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84315

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |egallager at gcc dot gnu.org

--- Comment #2 from Eric Gallager <egallager at gcc dot gnu.org> ---
-Wnull-dereference gets test case 1:

$ /usr/local/bin/gcc -c -O2 -S -Wall -Wnonnull
-fdump-tree-optimized=/dev/stdout -Wextra -pedantic -Wnull-dereference
-Warray-bounds=2 84315_1.c
84315_1.c: In function 'main':
84315_1.c:4:11: warning: null pointer dereference [-Wnull-dereference]
   return p[123];   // missing -Wnonnull
          ~^~~~~

;; Function main (main, funcdef_no=0, decl_uid=1904, cgraph_uid=0,
symbol_order=0) (executed once)

main ()
{
  int _2;

  <bb 2> [local count: 1073741825]:
  _2 ={v} MEM[(int *)0B + 492B];
  __builtin_trap ();

}


$

It also gets test case 2:

$ /usr/local/bin/gcc -c -O2 -S -Wall -Wnonnull
-fdump-tree-optimized=/dev/stdout -Wextra -pedantic -Wnull-dereference
-Warray-bounds=2 84315_2.c

;; Function f (f, funcdef_no=0, decl_uid=1905, cgraph_uid=0, symbol_order=1)

f (unsigned int i)
{
  int * iftmp.0_1;

  <bb 2> [local count: 1073741825]:
  if (i_2(D) <= 31)
    goto <bb 4>; [71.00%]
  else
    goto <bb 3>; [29.00%]

  <bb 3> [local count: 311385128]:

  <bb 4> [local count: 1073741825]:
  # iftmp.0_1 = PHI <&a(2), 0B(3)>
  return iftmp.0_1;

}


84315_2.c: In function 'main':
84315_2.c:11:10: warning: null pointer dereference [-Wnull-dereference]
   return *p;   // missing -Wnonnull
          ^~

;; Function main (main, funcdef_no=1, decl_uid=1908, cgraph_uid=1,
symbol_order=2) (executed once)

main ()
{
  int _2;

  <bb 2> [local count: 1073741825]:
  _2 ={v} MEM[(int *)0B];
  __builtin_trap ();

}


$

I think just the -Wnull-dereference warning is fine; no need for -Wnonnull to
warn about it, too.