[Bug middle-end/99959] New: missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[Bug middle-end/99959] New: missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

            Bug ID: 99959
           Summary: missing -Wuninitialized for an esra variable with
                    TREE_NO_WARNING
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: msebor at gcc dot gnu.org
  Target Milestone: ---

GCC fails to issue -Wuninitialized for the following test case derived from
pr99945.  The warning detects the uninitialized use but the SR.3 variable has
the TREE_NO_WARNING bit set which suppresses it.

$ cat z.c && gcc -O2 -S -Wall -fdump-tree-esra=/dev/stdout z.c
void g (void)
{
  int i;

  void f (int *t)
  {
    __builtin_printf ("%i", i);   // missing -Wuninitialized
  }

  int t __attribute__ ((cleanup (f))) = 0;
}


;; Function f (f.0, funcdef_no=1, decl_uid=1947, cgraph_uid=1, symbol_order=0)

void f (int * t)
{
  int _3;

  <bb 2> :
  _3 = CHAIN.1_2(D)->i;
  __builtin_printf ("%i", _3);
  return;

}



;; Function g (g, funcdef_no=0, decl_uid=1943, cgraph_uid=2, symbol_order=1)

Created a replacement for FRAME.0 offset: 0, size: 32: SR.3D.1962
void g ()
{
  int SR.3;
  struct FRAME.g FRAME.0;
  int t;
  void * _3;
  int _8;

  <bb 2> :
  _3 = __builtin_dwarf_cfa (0);
  FRAME.0.FRAME_BASE.PARENT = _3;
  _8 = SR.3_10(D);
  __builtin_printf ("%i", _8);
  return;

}

[Bug middle-end/99959] [9/10/11 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|missing -Wuninitialized for |[9/10/11 Regression]
                   |an esra variable with       |missing -Wuninitialized for
                   |TREE_NO_WARNING             |an esra variable with
                   |                            |TREE_NO_WARNING
           Keywords|                            |diagnostic
      Known to fail|                            |10.2.0, 11.0, 6.3.0, 7.0.1,
                   |                            |8.3.0, 9.3.0
             Blocks|                            |24639

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
The warning has been suppressed since r230968 (6.0.0 20151126).  Until then,
GCC issued:

pr99959.c:7:5: warning: ‘FRAME.0.i’ is used uninitialized in this function
[-Wuninitialized]
     __builtin_printf ("%i", i);   // missing -Wuninitialized
     ^~~~~~~~~~~~~~~~~~~~~~~~~~


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24639
[Bug 24639] [meta-bug] bug to track all Wuninitialized issues

[Bug middle-end/99959] [9/10/11 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |9.4

[Bug middle-end/99959] [9/10/11 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug middle-end/99959] [9/10/11/12 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.4                         |9.5

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug middle-end/99959] [9/10/11/12 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

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

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

--- Comment #3 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Martin Sebor from comment #1)
> The warning has been suppressed since r230968 (6.0.0 20151126).  Until then,
> GCC issued:
> 
> pr99959.c:7:5: warning: ‘FRAME.0.i’ is used uninitialized in this function
> [-Wuninitialized]
>      __builtin_printf ("%i", i);   // missing -Wuninitialized
>      ^~~~~~~~~~~~~~~~~~~~~~~~~~

did your TREE_NO_WARNING overhaul affect this at all?

[Bug middle-end/99959] [9/10/11/12 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
No, that change (r12-1805 and related) doesn't affect these cases (and wasn't
expected to; the warning is still suppressed in the esra pass).

[Bug middle-end/99959] [10/11/12/13 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug middle-end/99959] [10/11/12/13 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug middle-end/99959] [11/12/13/14 Regression] missing -Wuninitialized for an esra variable with TREE_NO_WARNING

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99959

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.