[Bug fortran/101917] New: Spurious -Wstringop-overread with -flto when passing zero sized arrays

[Bug fortran/101917] New: Spurious -Wstringop-overread with -flto when passing zero sized arrays

[rimvydas.jas at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101917

            Bug ID: 101917
           Summary: Spurious -Wstringop-overread with -flto when passing
                    zero sized arrays
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rimvydas.jas at gmail dot com
  Target Milestone: ---

$ cat bar.c
void bar_(const int flag[], const int *num) { }

$ cat foo.f90
program foo
integer :: idummy(0)
call bar(idummy, 0)
end program

$ gcc -flto -c bar.c
$ gfortran -Wall -Wextra -flto -c foo.f90
$ gfortran -Wall -Wextra -flto foo.o bar.o
foo.f90: In function 'foo':
foo.f90:3:19: warning: 'bar_' reading 4 bytes from a region of size 0
[-Wstringop-overread]
    3 | call bar(idummy, 0)
      |                   ^
foo.f90:3:19: note: referencing argument 1 of type 'const int *'
bar.c:1:6: note: in a call to function 'bar_'
    1 | void bar_(const int flag[], const int *num) { }
      |      ^

[Bug middle-end/101917] [11 Regression] Spurious -Wstringop-overread with -flto when passing zero sized arrays

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101917

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|fortran                     |middle-end
            Summary|Spurious                    |[11 Regression] Spurious
                   |-Wstringop-overread with    |-Wstringop-overread with
                   |-flto when passing zero     |-flto when passing zero
                   |sized arrays                |sized arrays
     Ever confirmed|0                           |1
      Known to fail|                            |11.2.0
             Blocks|                            |97048
   Last reconfirmed|                            |2021-11-10
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=103145

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Confirmed with GCC 11, but fixed in GCC 12.  Most likely a duplicate of
pr103145.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97048
[Bug 97048] [meta-bug] bogus/missing -Wstringop-overread warnings

[Bug middle-end/101917] [11 Regression] Spurious -Wstringop-overread with -flto when passing zero sized arrays

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101917

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.3
           Priority|P3                          |P2

[Bug middle-end/101917] [11 Regression] Spurious -Wstringop-overread with -flto when passing zero sized arrays

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101917

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.3                        |11.4

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.3 is being released, retargeting bugs to GCC 11.4.

[Bug middle-end/101917] [11 Regression] Spurious -Wstringop-overread with -flto when passing zero sized arrays

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101917

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.4                        |11.5

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.4 is being released, retargeting bugs to GCC 11.5.