[Bug c/95124] New: internal compiler error: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in diag_attr_exclusions, at attribs.c:396

[Bug c/95124] New: internal compiler error: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in diag_attr_exclusions, at attribs.c:396

[anbu1024.me at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95124

            Bug ID: 95124
           Summary: internal compiler error: tree check: expected class
                    ‘type’, have ‘exceptional’ (error_mark) in
                    diag_attr_exclusions, at attribs.c:396
           Product: gcc
           Version: 10.0
            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 reduced.c 

int foo () { 
        x; 

        void bar ( ) 
        { 
                struct struct_0 * var_5 = ( { int x  __attribute__ ( ( unused ,
section ( ".text" ) ) ) ; } )
        }
}


$ gcc-10 --version
gcc (GCC) 10.0.1 20200419 (experimental)
Copyright (C) 2020 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-10 reduced.c 
reduced.c: In function ‘foo’:
reduced.c:3:2: error: ‘x’ undeclared (first use in this function)
    3 |  x;
      |  ^
reduced.c:3:2: note: each undeclared identifier is reported only once for each
function it appears in
reduced.c: In function ‘bar’:
reduced.c:7:10: internal compiler error: tree check: expected class ‘type’,
have ‘exceptional’ (error_mark) in diag_attr_exclusions, at attribs.c:396
    7 |   struct struct_0 * var_5 = ( { int x  __attribute__ ( ( unused ,
section ( ".text" ) ) ) ; } )
      |          ^~~~~~~~
0x731f2f tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
        ../../gcc-10-20200419/gcc/tree.c:9777
0x5eaf44 tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)
        ../../gcc-10-20200419/gcc/tree.h:3410
0x5eaf44 diag_attr_exclusions
        ../../gcc-10-20200419/gcc/attribs.c:396
0x7d4fda diag_attr_exclusions
        ../../gcc-10-20200419/gcc/attribs.c:379
0x7d6fb5 decl_attributes(tree_node**, tree_node*, int, tree_node*)
        ../../gcc-10-20200419/gcc/attribs.c:694
0x7f2554 start_decl(c_declarator*, c_declspecs*, bool, tree_node*)
        ../../gcc-10-20200419/gcc/c/c-decl.c:5117
0x84cdd5 c_parser_declaration_or_fndef
        ../../gcc-10-20200419/gcc/c/c-parser.c:2271
0x8302bf c_parser_compound_statement_nostart
        ../../gcc-10-20200419/gcc/c/c-parser.c:5718
0x831f6f c_parser_postfix_expression
        ../../gcc-10-20200419/gcc/c/c-parser.c:9113
0x834ada c_parser_unary_expression
        ../../gcc-10-20200419/gcc/c/c-parser.c:8273
0x83632d c_parser_cast_expression
        ../../gcc-10-20200419/gcc/c/c-parser.c:8115
0x8365b9 c_parser_binary_expression
        ../../gcc-10-20200419/gcc/c/c-parser.c:7918
0x837595 c_parser_conditional_expression
        ../../gcc-10-20200419/gcc/c/c-parser.c:7652
0x837bb0 c_parser_expr_no_commas
        ../../gcc-10-20200419/gcc/c/c-parser.c:7569
0x83aa4c c_parser_initializer
        ../../gcc-10-20200419/gcc/c/c-parser.c:5227
0x83aa4c c_parser_initializer
        ../../gcc-10-20200419/gcc/c/c-parser.c:5219
0x84d193 c_parser_declaration_or_fndef
        ../../gcc-10-20200419/gcc/c/c-parser.c:2248
0x8302bf c_parser_compound_statement_nostart
        ../../gcc-10-20200419/gcc/c/c-parser.c:5718
0x84c8c4 c_parser_compound_statement
        ../../gcc-10-20200419/gcc/c/c-parser.c:5617
0x84e381 c_parser_declaration_or_fndef
        ../../gcc-10-20200419/gcc/c/c-parser.c:2505
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-9 --version
gcc (GCC) 9.3.1 20200425
Copyright (C) 2019 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-9 reduced.c 
reduced.c: In function ‘foo’:
reduced.c:3:2: error: ‘x’ undeclared (first use in this function)
    3 |  x;
      |  ^
reduced.c:3:2: note: each undeclared identifier is reported only once for each
function it appears in
reduced.c: In function ‘bar’:
reduced.c:7:37: error: section attribute cannot be specified for local
variables
    7 |   struct struct_0 * var_5 = ( { int x  __attribute__ ( ( unused ,
section ( ".text" ) ) ) ; } )
      |                                     ^
reduced.c:7:29: error: void value not ignored as it ought to be
    7 |   struct struct_0 * var_5 = ( { int x  __attribute__ ( ( unused ,
section ( ".text" ) ) ) ; } )
      |                             ^
reduced.c:8:2: error: expected ‘,’ or ‘;’ before ‘}’ token
    8 |  }
      |  ^
reduced.c: In function ‘foo’:
reduced.c:9:1: error: expected declaration or statement at end of input
    9 | }
      | ^

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

$ gcc-8 --version
gcc (GCC) 8.4.1 20200424
Copyright (C) 2018 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-8 reduced.c 
reduced.c: In function ‘foo’:
reduced.c:3:2: error: ‘x’ undeclared (first use in this function)
  x;
  ^
reduced.c:3:2: note: each undeclared identifier is reported only once for each
function it appears in
reduced.c: In function ‘bar’:
reduced.c:7:37: error: section attribute cannot be specified for local
variables
   struct struct_0 * var_5 = ( { int x  __attribute__ ( ( unused , section (
".text" ) ) ) ; } )
                                     ^
reduced.c:7:29: error: void value not ignored as it ought to be
   struct struct_0 * var_5 = ( { int x  __attribute__ ( ( unused , section (
".text" ) ) ) ; } )
                             ^
reduced.c:8:2: error: expected ‘,’ or ‘;’ before ‘}’ token
  }
  ^
reduced.c: In function ‘foo’:
reduced.c:9:1: error: expected declaration or statement at end of input
 }
 ^

[Bug c/95124] internal compiler error: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in diag_attr_exclusions, at attribs.c:396

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95124

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Looks like this is fixed, I cannot even reproduce it with GCC 10.1.0.