[Bug c/110699] New: internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[Bug c/110699] New: internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[141242068 at smail dot nju.edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110699

            Bug ID: 110699
           Summary: internal compiler error: tree check: expected
                    array_type, have error_mark in array_ref_low_bound, at
                    tree.cc:12754
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: 141242068 at smail dot nju.edu.cn
  Target Milestone: ---

When compiling below program using gcc-14 with option `gcc-14 a.c`, gcc-14
crashes:
```
typedef __attribute__((__vector_size__(64))) int T;

void f(void) {
  extern char a[64], b[64];
  void *p = a;
  T q = *(T *)&b[0];
}

void g() {
  extern char b;
}
```

GCC's output is pasted below:
```
<source>: In function 'g':
<source>:10:15: error: conflicting types for 'b'; have 'char'
   10 |   extern char b;
      |               ^
<source>:4:22: note: previous declaration of 'b' with type 'char[64]'
    4 |   extern char a[64], b[64];
      |                      ^
<source>: In function 'f':
<source>:6:17: internal compiler error: tree check: expected array_type, have
error_mark in array_ref_low_bound, at tree.cc:12754
    6 |   T q = *(T *)&b[0];
      |                ~^~~
0x215104e internal_error(char const*, ...)
        ???:0
0x896b1b tree_check_failed(tree_node const*, char const*, int, char const*,
...)
        ???:0
0xd6c895 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ???:0
0xd6d557 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ???:0
0xd6db1d gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ???:0
0xd6cf6a gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ???:0
0xd7053a gimplify_stmt(tree_node**, gimple**)
        ???:0
0xd6d53e gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ???:0
0xd7053a gimplify_stmt(tree_node**, gimple**)
        ???:0
0xd6e4ab gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ???:0
0xd7053a gimplify_stmt(tree_node**, gimple**)
        ???:0
0xd6d914 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ???:0
0xd7053a gimplify_stmt(tree_node**, gimple**)
        ???:0
0xd719d3 gimplify_body(tree_node*, bool)
        ???:0
0xd71e2f gimplify_function_tree(tree_node*)
        ???:0
0xbaeba7 cgraph_node::analyze()
        ???:0
0xbb26f1 symbol_table::finalize_compilation_unit()
        ???:0
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
```

This can be verified by visiting the Compiler Explorer:
https://gcc.godbolt.org/z/jPhnfG4f3

[Bug c/110699] [12/13/14 Regression] internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110699

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-07-17
   Target Milestone|---                         |12.4
            Summary|internal compiler error:    |[12/13/14 Regression]
                   |tree check: expected        |internal compiler error:
                   |array_type, have error_mark |tree check: expected
                   |in array_ref_low_bound, at  |array_type, have error_mark
                   |tree.cc:12754               |in array_ref_low_bound, at
                   |                            |tree.cc:12754
     Ever confirmed|0                           |1
                 CC|                            |mpolacek at gcc dot gnu.org

[Bug c/110699] [12/13/14 Regression] internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110699

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

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

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Started with r12-3278:

commit 823685221de986afb729910a6f2237f07a377f17
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Wed Sep 1 08:38:39 2021 +0100

    C: PR c/79412: Poison decls with error_mark_node after type mismatch

[Bug c/110699] [12/13/14 Regression] internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |trivial

[Bug c/110699] [12/13/14 Regression] internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110699

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Roger Sayle <sayle@gcc.gnu.org>:

https://gcc.gnu.org/g:cfe53af09364d94fb86013f85ef598a1d47e0657

commit r14-2721-gcfe53af09364d94fb86013f85ef598a1d47e0657
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Fri Jul 21 20:37:59 2023 +0100

    PR c/110699: Defend against error_mark_node in gimplify.cc.

    This patch resolves PR c/110669, an ICE-after-error regression, by adding
    a check that the array type isn't error_mark_node in
gimplify_compound_lval.

    2023-07-21  Roger Sayle  <roger@nextmovesoftware.com>
                Richard Biener  <rguenther@suse.de>

    gcc/ChangeLog
            PR c/110699
            * gimplify.cc (gimplify_compound_lval):  If the array's type
            is error_mark_node then return GS_ERROR.

    gcc/testsuite/ChangeLog
            PR c/110699
            * gcc.dg/pr110699.c: New test case.

[Bug c/110699] [12/13/14 Regression] internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[roger at nextmovesoftware dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110699

Roger Sayle <roger at nextmovesoftware dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |roger at nextmovesoftware dot com
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #3 from Roger Sayle <roger at nextmovesoftware dot com> ---
This issue has been fixed on mainline for GCC 14.

[Bug c/110699] [12/13/14 Regression] internal compiler error: tree check: expected array_type, have error_mark in array_ref_low_bound, at tree.cc:12754

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|12.4                        |14.0