[Bug c/109521] New: Checking ICE (canonical types differ for identical types)

[Bug c/109521] New: Checking ICE (canonical types differ for identical types)

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109521

            Bug ID: 109521
           Summary: Checking ICE (canonical types differ for identical
                    types)
           Product: gcc
           Version: 13.0
               URL: https://bugs.gentoo.org/904339
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sjames at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu
             Build: x86_64-pc-linux-gnu

Created attachment 54865
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54865&action=edit
optimise.ii.orig.xz

Had this when building form-4.3.0. Originally reported downstream in Gentoo at
https://bugs.gentoo.org/904339.

To trigger this, I had to use -U_GLIBCXX_ASSERTIONS as I have it enabled by
default for my GCC (Gentoo has it enabled by default for hardened, but not all
setups). Obviously this doesn't matter once preprocessed though.

Needs a checking build.

```
$ g++ -DHAVE_CONFIG_H -I. -I.. -O2 -Wall -Wextra -Wpadded
-Wno-misleading-indentation -Wno-stringop-overflow -U_GLIBCXX_ASSERTIONS -c
sources/optimize.cc
‘
during GIMPLE pass: uninit
In function ‘void find_Horner_MCTS()’:
canonical types differ for identical types ‘UBYTE [7]’ {aka ‘unsigned char
[7]’} and ‘unsigned char [7]’
 2208 | void find_Horner_MCTS () {
      |      ^~~~~~~~~~~~~~~~
0x68ea0a comptypes(tree_node*, tree_node*, int)
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/cp/typeck.cc:1710
0x22768b9 cxx_types_compatible_p(tree_node*, tree_node*)
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/cp/cp-objcp-common.cc:130
0x11ed84a c_fold_indirect_ref_for_warn
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/c-family/c-pretty-print.cc:1851
0x11edf79 c_fold_indirect_ref_for_warn
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/c-family/c-pretty-print.cc:1918
0x11ee249 print_mem_ref
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/c-family/c-pretty-print.cc:1981
0x7b8b72 expr_to_string(tree_node*)
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/cp/error.cc:3315
0x21adbb0 cp_printer
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/cp/error.cc:4484
0x1a71e85 pp_format(pretty_printer*, text_info*)
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/pretty-print.cc:1475
0x1a710c3 diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/diagnostic.cc:1592
0x1aef8c9 diagnostic_impl
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/diagnostic.cc:1756
0x1aef8c9 warning_at(unsigned int, int, char const*, ...)
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/diagnostic.cc:1893
0x9eda7e maybe_warn_operand
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/tree-ssa-uninit.cc:731
0x1d83413 warn_uninitialized_vars
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/tree-ssa-uninit.cc:1098
0x22271fa execute_late_warn_uninitialized
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/tree-ssa-uninit.cc:1406
0x22271fa execute
       
/usr/src/debug/sys-devel/gcc-13.0.1_pre20230409-r4/gcc-13-20230409/gcc/tree-ssa-uninit.cc:1451
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://bugs.gentoo.org/> for instructions.
```

Reduction in progress.

[Bug c++/109521] [11/12/13 Regression] Checking ICE with canonical types differ for identical types ‘UBYTE [7]’ {aka ‘unsigned char [7]’} and ‘unsigned char [7]’

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109521

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|11.3.1, 12.2.1, 13.0        |11.1.0
      Known to work|10.4.1                      |10.4.0
   Target Milestone|---                         |11.4
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |ice-checking,
                   |                            |ice-on-valid-code,
                   |                            |needs-bisection
            Summary|[11/12/13 regression]       |[11/12/13 Regression]
                   |Checking ICE with canonical |Checking ICE with canonical
                   |types differ for identical  |types differ for identical
                   |types ‘UBYTE [7]’ {aka      |types ‘UBYTE [7]’ {aka
                   |‘unsigned char [7]’} and    |‘unsigned char [7]’} and
                   |‘unsigned char [7]’         |‘unsigned char [7]’
   Last reconfirmed|                            |2023-04-15

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced:
```
struct vector
{
  vector&       operator=(vector&& __x)
  {
    return *this;
  }
};
struct tree_node {
  vector childs;
  unsigned char pad[7];
  tree_node(){}
};
tree_node mcts_root;
void find_Horner_MCTS_expand_tree () {
    mcts_root =  tree_node();
}
```
Compile at -O2 -Wall is enough to reproduce the failure.
Note using unsigned short or unsigned int instead of unsigned char allows it to
work.

[Bug c++/109521] [11/12/13 Regression] Checking ICE with canonical types differ for identical types ‘UBYTE [7]’ {aka ‘unsigned char [7]’} and ‘unsigned char [7]’

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109521

--- Comment #2 from Sam James <sjames at gcc dot gnu.org> ---
Created attachment 54866
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54866&action=edit
reduced.ii

Yours is better formed, I think, but let me attach the results of cvise which
just finished for the hell of it.

[Bug c++/109521] [11/12/13 Regression] Checking ICE with canonical types differ for identical types ‘UBYTE [7]’ {aka ‘unsigned char [7]’} and ‘unsigned char [7]’ since r11-6508-gabb1b6058c09a7

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109521

Sam James <sjames at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11/12/13 Regression]       |[11/12/13 Regression]
                   |Checking ICE with canonical |Checking ICE with canonical
                   |types differ for identical  |types differ for identical
                   |types ‘UBYTE [7]’ {aka      |types ‘UBYTE [7]’ {aka
                   |‘unsigned char [7]’} and    |‘unsigned char [7]’} and
                   |‘unsigned char [7]’         |‘unsigned char [7]’ since
                   |                            |r11-6508-gabb1b6058c09a7
                 CC|                            |msebor at gcc dot gnu.org

--- Comment #3 from Sam James <sjames at gcc dot gnu.org> ---
Bisect says:

abb1b6058c09a7c0430d9bf019466ada07ca7b40 is the first bad commit
commit abb1b6058c09a7c0430d9bf019466ada07ca7b40
Author: Martin Sebor <msebor@redhat.com>
Date:   Wed Jan 6 13:44:27 2021 -0700

    PR c++/95768 - pretty-printer ICE on -Wuninitialized with allocated storage

i.e. r11-6508-gabb1b6058c09a7.

[Bug c++/109521] [11/12/13 Regression] Checking ICE with canonical types differ for identical types ‘UBYTE [7]’ {aka ‘unsigned char [7]’} and ‘unsigned char [7]’ since r11-6508-gabb1b6058c09a7

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109521

--- Comment #4 from Sam James <sjames at gcc dot gnu.org> ---
Note that it's also missing the 'internal compiler error' message in the
output.

[Bug c++/109521] [11/12/13 Regression] Checking ICE with canonical types differ for identical types ‘UBYTE [7]’ {aka ‘unsigned char [7]’} and ‘unsigned char [7]’ since r11-6508-gabb1b6058c09a7

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109521

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

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

[Bug c++/109521] [11/12/13/14 Regression] Checking ICE with canonical types differ for identical types ‘UBYTE [7]’ {aka ‘unsigned char [7]’} and ‘unsigned char [7]’ since r11-6508-gabb1b6058c09a7

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109521

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

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

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.4 is being released, retargeting bugs to GCC 11.5.