[Bug middle-end/92815] [8/9/10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[Bug middle-end/92815] [8/9/10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2019-12-05 00:00:00         |2020-4-22
      Known to fail|                            |10.0, 8.2.0, 9.2.0
           Keywords|                            |patch

--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> ---
Patch: https://gcc.gnu.org/pipermail/gcc-patches/2020-April/544369.html

[Bug middle-end/92815] [8/9/10/11 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Martin Sebor <msebor@gcc.gnu.org>:

https://gcc.gnu.org/g:7a41fcde6c67faafab8c8ee2a31140999383dcef

commit r11-470-g7a41fcde6c67faafab8c8ee2a31140999383dcef
Author: Martin Sebor <msebor@redhat.com>
Date:   Mon May 18 15:24:12 2020 -0600

    PR middle-end/92815 - spurious -Wstringop-overflow writing into a flexible
array of an extern struct

    gcc/ChangeLog:

            PR middle-end/92815
            * tree-object-size.c (decl_init_size): New function.
            (addr_object_size): Call it.
            * tree.h (last_field): Declare.
            (first_field): Add attribute nonnull.

    gcc/testsuite/ChangeLog:

            PR middle-end/92815
            * gcc.dg/Warray-bounds-56.c: Remove xfails.
            * gcc.dg/builtin-object-size-20.c: New test.
            * gcc.dg/builtin-object-size-21.c: New test.

[Bug middle-end/92815] [8/9/10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |11.0
            Summary|[8/9/10/11 Regression]      |[8/9/10 Regression]
                   |spurious                    |spurious
                   |-Wstringop-overflow writing |-Wstringop-overflow writing
                   |into a flexible array of an |into a flexible array of an
                   |extern struct               |extern struct

--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
Fixed on trunk for now.

[Bug middle-end/92815] [8/9/10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Martin Sebor <msebor@gcc.gnu.org>:

https://gcc.gnu.org/g:8edf0adb6616bd717312d9b305c7d7c9a6b7a171

commit r11-472-g8edf0adb6616bd717312d9b305c7d7c9a6b7a171
Author: Martin Sebor <msebor@redhat.com>
Date:   Mon May 18 16:31:13 2020 -0600

    PR middle-end/92815 - spurious -Wstringop-overflow writing into a flexible
array of an extern struct

    Adjust test to avoid failures in ILP32 mode.

    gcc/testsuite/ChangeLog:

            PR middle-end/92815
            * gcc.dg/builtin-object-size-20.c: Adjust to avoid failures in
            ILP32 mode.

[Bug middle-end/92815] [8/9/10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

Arseny Solokha <asolokha at gmx dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |asolokha at gmx dot com

--- Comment #9 from Arseny Solokha <asolokha at gmx dot com> ---
Created attachment 48593
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48593&action=edit
Diff between assembler output produced by gcc and g++ 11

Though there are no flexible array members in C++, is it expected for g++ to
behave differently w/ this testcase?

While compiling it w/ gcc yeilds the following, which is expected:

% gcc-11.0.0 -c gcc/testsuite/gcc.dg/builtin-object-size-21.c
gcc/testsuite/gcc.dg/builtin-object-size-21.c:29:14: error: size of variable
'xm3_4' is too large
   29 | struct Ax_m3 xm3_4 = { { 0 }, { 1, 2, 3, 3 } };   // { dg-error "too
large" }
      |              ^~~~~
gcc/testsuite/gcc.dg/builtin-object-size-21.c:43:14: error: size of variable
'xmx_1' is too large
   43 | struct Ax_mx xmx_1 = { { 0 }, { 1 } };            // { dg-error "too
large" }
      |

W/ g++ I have

% g++-11.0.0 -c gcc/testsuite/gcc.dg/builtin-object-size-21.c
/tmp/ccPBumhF.s: Assembler messages:
/tmp/ccPBumhF.s: Fatal error: can't write 14 bytes to section .text of
/tmp/ccj6lymE.o: 'file truncated'
/usr/lib/gcc/x86_64-unknown-linux-gnu/11.0.0/../../../../x86_64-unknown-linux-gnu/bin/as:
BFD (Gentoo 2.34 p4) 2.34.0 assertion fail
/var/tmp/portage/sys-devel/binutils-2.34-r1/work/binutils-2.34/bfd/elf.c:3169
/tmp/ccPBumhF.s: Fatal error: can't close /tmp/ccj6lymE.o: file truncated

because of

[pid 1165642] openat(AT_FDCWD, "builtin-object-size-21.o",
O_RDWR|O_CREAT|O_TRUNC, 0666) = 3
<…>
[pid 1165642] fstat(3, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
[pid 1165642] lseek(3, -9223372036854775808, SEEK_SET) = -1 EINVAL (Invalid
argument)

Or, when writing to an "endless" file w/ -o /dev/null:

[pid 1164514] lseek(3, -9223372036854775808, SEEK_SET) = 0
[pid 1164514] read(3, "", 640)          = 0
[pid 1164514] lseek(3, 640, SEEK_CUR)   = 0
[pid 1164514] write(3, "\0builtin-object-size-21.c\0xm3_0\0"..., 96) = 96
[pid 1164514] lseek(3, 0, SEEK_SET)     = 0
[pid 1164514] read(3, "", 4096)         = 0
[pid 1164514] lseek(3, 64, SEEK_CUR)    = 0
[pid 1164514] write(3, "UH\211\345\220]\303UH\211\345\220]\303", 14) = 14
[pid 1164514] lseek(3, 0, SEEK_SET)     = 0
[pid 1164514] read(3, "", 4096)         = 0
[pid 1164514] lseek(3, 96, SEEK_CUR)    = 0
[pid 1164514] write(3,
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) =
4096
[pid 1164514] write(3,
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) =
4096
[pid 1164514] write(3,
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) =
4096

[Bug middle-end/92815] [9/10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.5                         |9.4

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 8 branch is being closed.

[Bug middle-end/92815] [9/10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

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

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

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug middle-end/92815] [10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

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

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

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug middle-end/92815] [10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

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

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

--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug middle-end/92815] [10 Regression] spurious -Wstringop-overflow writing into a flexible array of an extern struct

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92815

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.0
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED
      Known to fail|                            |10.5.0

--- Comment #14 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed in GCC 11.