[Bug tree-optimization/100250] New: ICE related to -Wmaybe-uninitialized

[Bug tree-optimization/100250] New: ICE related to -Wmaybe-uninitialized

[muecker at gwdg dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

            Bug ID: 100250
           Summary: ICE related to -Wmaybe-uninitialized
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: muecker at gwdg dot de
  Target Milestone: ---

Created attachment 50670
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50670&action=edit
minimized test case

(possibly also affects 11.0)

xgcc (GCC) 12.0.0 20210424 (experimental)
bcd77b7b9f35bd5b559ed593c3b3e346c1e6f364



$ ../gcc_build_clean/gcc/xgcc -B../gcc_build_clean/gcc/ -Wmaybe-uninitialized
ice.c
ice.c: In function ‘md_reshape2’:
ice.c:34:9: warning: ‘<unknown>’ may be used uninitialized
[-Wmaybe-uninitialized]
   34 |         md_permute2(D, order, dims2, strs2, idims);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
during GIMPLE pass: *early_warn_uninitialized
ice.c:35:1: internal compiler error: Speicherzugriffsfehler
   35 | }
      | ^
0xe00f3f crash_signal
        ../../gcc/gcc/toplev.c:327
0x7f26a437583f ???
       
/build/glibc-vjB4T1/glibc-2.28/signal/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0
0x80db7c tree_check(tree_node*, char const*, int, char const*, tree_code)
        ../../gcc/gcc/tree.h:3352
0x80db7c attr_access::array_as_string[abi:cxx11](tree_node*) const
        ../../gcc/gcc/attribs.c:2391
0x101789d maybe_warn_pass_by_reference
        ../../gcc/gcc/tree-ssa-uninit.c:566
0x101789d warn_uninitialized_vars
        ../../gcc/gcc/tree-ssa-uninit.c:648
0x1017c70 execute_early_warn_uninitialized
        ../../gcc/gcc/tree-ssa-uninit.c:3089
0x1017c70 execute
        ../../gcc/gcc/tree-ssa-uninit.c:3124
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug tree-optimization/100250] [11/12 Regression] ICE related to -Wmaybe-uninitialized

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
             Blocks|                            |24639
                 CC|                            |msebor at gcc dot gnu.org
   Target Milestone|---                         |11.2
      Known to work|                            |10.3.0
           Priority|P3                          |P2
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-04-26
     Ever confirmed|0                           |1
            Summary|ICE related to              |[11/12 Regression] ICE
                   |-Wmaybe-uninitialized       |related to
                   |                            |-Wmaybe-uninitialized

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.


Referenced Bugs:

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

[Bug tree-optimization/100250] [11/12 Regression] ICE related to -Wmaybe-uninitialized

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
This is a consequence of fixing pr97172 by clearing the VLA bounds encoded by
the front end in function attributes before the IL enters the middle end: they
VLA bounds aren't used to decide whether to diagnose code but they are used in
the text of the warnings.  That's why the originally submitted patches
preserved them (v2 of the patch encoded them as strings:
https://gcc.gnu.org/pipermail/gcc-patches/2020-December/562318.html)

[Bug tree-optimization/100250] [11/12 Regression] ICE related to -Wmaybe-uninitialized

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |msebor at gcc dot gnu.org
      Known to fail|                            |11.0, 12.0

[Bug tree-optimization/100250] [11/12 Regression] ICE related to -Wmaybe-uninitialized

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
Patch: https://gcc.gnu.org/pipermail/gcc-patches/2021-April/568764.html

[Bug tree-optimization/100250] [11/12 Regression] ICE related to -Wmaybe-uninitialized

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

--- Comment #4 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:2c8bffa184dffba7976ba807ef0a1bbb6f66aa2d

commit r12-246-g2c8bffa184dffba7976ba807ef0a1bbb6f66aa2d
Author: Martin Sebor <msebor@redhat.com>
Date:   Wed Apr 28 19:11:34 2021 -0600

    PR middle-end/100250 - ICE related to -Wmaybe-uninitialized

    gcc/ChangeLog:

            PR middle-end/100250
            * attribs.c (attr_access::array_as_string): Avoid dereferencing
            a pointer when it's null.

    gcc/testsuite/ChangeLog:

            PR middle-end/100250
            * gcc.dg/uninit-pr100250.c: New test.

[Bug tree-optimization/100250] [11 Regression] ICE related to -Wmaybe-uninitialized

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|11.0, 12.0                  |11.1.0
      Known to work|                            |12.0
            Summary|[11/12 Regression] ICE      |[11 Regression] ICE related
                   |related to                  |to -Wmaybe-uninitialized
                   |-Wmaybe-uninitialized       |

--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> ---
Fixed in 12.0 for now.

[Bug tree-optimization/100250] [11 Regression] ICE related to -Wmaybe-uninitialized

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |christian.holme at med dot uni-goe
                   |                            |ttingen.de

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
*** Bug 100924 has been marked as a duplicate of this bug. ***

[Bug tree-optimization/100250] [11 Regression] ICE related to -Wmaybe-uninitialized

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |heinrich.heinzer at gmail dot com

--- Comment #7 from Martin Liška <marxin at gcc dot gnu.org> ---
*** Bug 101092 has been marked as a duplicate of this bug. ***

[Bug tree-optimization/100250] [11 Regression] ICE related to -Wmaybe-uninitialized

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Martin Sebor
<msebor@gcc.gnu.org>:

https://gcc.gnu.org/g:a52b2f4cae38abecda2a7ad72a47c4e38236870a

commit r11-8599-ga52b2f4cae38abecda2a7ad72a47c4e38236870a
Author: Martin Sebor <msebor@redhat.com>
Date:   Thu Jun 17 10:20:09 2021 -0600

    Backported from trunk:

    PR middle-end/100250 - ICE related to -Wmaybe-uninitialized

    gcc/ChangeLog:

            PR middle-end/100250
            * attribs.c (attr_access::array_as_string): Avoid dereferencing
            a pointer when it's null.

    gcc/testsuite/ChangeLog:

            PR middle-end/100250
            * gcc.dg/uninit-pr100250.c: New test.

[Bug tree-optimization/100250] [11 Regression] ICE related to -Wmaybe-uninitialized

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100250

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #9 from Martin Sebor <msebor at gcc dot gnu.org> ---
Backported to GCC 11.2.