[Bug c/101196] New: [12 Regression] ICE: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in useless_type_conversion_p

[anbu1024.me at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101196

            Bug ID: 101196
           Summary: [12 Regression] ICE: tree check: expected class
                    ‘type’, have ‘exceptional’ (error_mark) in
                    useless_type_conversion_p
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anbu1024.me at gmail dot com
  Target Milestone: ---

$ cat 37.c 

extern int var[16];

void foo(int [x]);

void bar(void)
{
  void foo(int array[]);
}

void baz(void)
{
  foo(var);
}

-------------------------------------------------------------------------------

$ gcc-sp12 --version
gcc (GCC) 12.0.0 20210620 (experimental)
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

-------------------------------------------------------------------------------

$ gcc-sp12 37.c 
37.c:4:15: error: ‘x’ undeclared here (not in a function)
    4 | void foo(int [x]);
      |               ^
37.c: In function ‘baz’:
37.c:13:7: error: type of formal parameter 1 is incomplete
   13 |   foo(var);
      |       ^~~
37.c:13:3: internal compiler error: tree check: expected class ‘type’, have
‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.c:259
   13 |   foo(var);
      |   ^~~
0x7a313c tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
        ../../gcc-12-20210620/gcc/tree.c:8734
0x6d5d8a tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)
        ../../gcc-12-20210620/gcc/tree.h:3494
0x6d5d8a useless_type_conversion_p(tree_node*, tree_node*)
        ../../gcc-12-20210620/gcc/gimple-expr.c:259
0xbc1108 types_compatible_p
        ../../gcc-12-20210620/gcc/gimple-expr.h:67
0xbc1108 gimplify_addr_expr
        ../../gcc-12-20210620/gcc/gimplify.c:6234
0xbb9384 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc-12-20210620/gcc/gimplify.c:14141
0xbc4dc4 gimplify_call_expr
        ../../gcc-12-20210620/gcc/gimplify.c:3454
0xbbacd4 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc-12-20210620/gcc/gimplify.c:14066
0xbbc9f6 gimplify_stmt(tree_node**, gimple**)
        ../../gcc-12-20210620/gcc/gimplify.c:6865
0xbbd14d gimplify_bind_expr
        ../../gcc-12-20210620/gcc/gimplify.c:1426
0xbbacee gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        ../../gcc-12-20210620/gcc/gimplify.c:14295
0xbd2229 gimplify_stmt(tree_node**, gimple**)
        ../../gcc-12-20210620/gcc/gimplify.c:6865
0xbd2229 gimplify_body(tree_node*, bool)
        ../../gcc-12-20210620/gcc/gimplify.c:15339
0xbd266d gimplify_function_tree(tree_node*)
        ../../gcc-12-20210620/gcc/gimplify.c:15493
0xa10bf7 cgraph_node::analyze()
        ../../gcc-12-20210620/gcc/cgraphunit.c:670
0xa135f7 analyze_functions
        ../../gcc-12-20210620/gcc/cgraphunit.c:1234
0xa1428d symbol_table::finalize_compilation_unit()
        ../../gcc-12-20210620/gcc/cgraphunit.c:2508
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.

-------------------------------------------------------------------------------

$ gcc-sp11 --version
gcc (GCC) 11.1.1 20210619
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

-------------------------------------------------------------------------------

$ gcc-sp11 37.c 
37.c:4:15: error: ‘x’ undeclared here (not in a function)
    4 | void foo(int [x]);
      |               ^
37.c: In function ‘baz’:
37.c:13:7: error: type of formal parameter 1 is incomplete
   13 |   foo(var);
      |       ^~~