[Bug c++/55801] New: ICE with thread_local after ill-formed forward declaration

["vlukas at gmx dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55801

             Bug #: 55801
           Summary: ICE with thread_local after ill-formed forward
                    declaration
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: vlukas@gmx.de


The following ill-formed snippet:
---------------------------------------------------------
class C;
class ::C;
thread_local C O, O2 = O;
--------------------------------------------------------

Compiled with "c++ -std=c++0x -c" produces an ICE:
--------------------------------------------------------
thread_local.ice.gcc-4.8.cc:2:9: warning: declaration 'class C' does not
declare anything [enabled by default]
 class ::C;
         ^
thread_local.ice.gcc-4.8.cc:3:16: error: aggregate 'C O' has incomplete type
and cannot be defined
 thread_local C O, O2 = O;
                ^
thread_local.ice.gcc-4.8.cc:3:19: error: variable 'C O2' has initializer but
incomplete type
 thread_local C O, O2 = O;
                   ^
thread_local.ice.gcc-4.8.cc:3:24: internal compiler error: tree check: expected
class 'type', have 'exceptional' (error_mark) in
var_defined_without_dynamic_init, at cp/decl2.c:2795
 thread_local C O, O2 = O;
                        ^
0xc6ef89 tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
        ../../gcc_svn/gcc/tree.c:9007
0x5e1bfc tree_class_check
        ../../gcc_svn/gcc/tree.h:3794
0x5e1bfc var_defined_without_dynamic_init
        ../../gcc_svn/gcc/cp/decl2.c:2795
0x5e1bfc var_needs_tls_wrapper
        ../../gcc_svn/gcc/cp/decl2.c:2813
0x5eeb6b get_tls_wrapper_fn(tree_node*)
        ../../gcc_svn/gcc/cp/decl2.c:2876
0x698816 finish_id_expression(tree_node*, tree_node*, tree_node*, cp_id_kind*,
bool, bool, bool*, bool, bool, bool, bool, char const**, unsigned int)
        ../../gcc_svn/gcc/cp/semantics.c:3296
0x61586d cp_parser_primary_expression
        ../../gcc_svn/gcc/cp/parser.c:4395
0x61736a cp_parser_postfix_expression
        ../../gcc_svn/gcc/cp/parser.c:5630
0x61987a cp_parser_unary_expression
        ../../gcc_svn/gcc/cp/parser.c:6686
0x61a3f7 cp_parser_binary_expression
        ../../gcc_svn/gcc/cp/parser.c:7360
0x61a885 cp_parser_assignment_expression
        ../../gcc_svn/gcc/cp/parser.c:7585
0x61acc4 cp_parser_constant_expression
        ../../gcc_svn/gcc/cp/parser.c:7816
0x626dfe cp_parser_init_declarator
        ../../gcc_svn/gcc/cp/parser.c:15986
0x62738e cp_parser_simple_declaration
        ../../gcc_svn/gcc/cp/parser.c:10562
0x629160 cp_parser_block_declaration
        ../../gcc_svn/gcc/cp/parser.c:10443
0x631d4b cp_parser_declaration
        ../../gcc_svn/gcc/cp/parser.c:10340
0x630a1d cp_parser_declaration_seq_opt
        ../../gcc_svn/gcc/cp/parser.c:10226
0x6322c2 cp_parser_translation_unit
        ../../gcc_svn/gcc/cp/parser.c:3808
0x6322c2 c_parse_file()
        ../../gcc_svn/gcc/cp/parser.c:28177
0x738854 c_common_parse_file()
        ../../gcc_svn/gcc/c-family/c-opts.c:1023
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
--------------------------------------------------------------

Output of "c++ -v" is:
--------------------------------------------------------------
 Using built-in specs.
COLLECT_GCC=/home/lima/vanilla_installs/gcc_and_tools/bin/c++
COLLECT_LTO_WRAPPER=/home/lima/vanilla_installs/gcc_and_tools/lib/gcc/x86_64-unknown-linux-gnu/4.8.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc_svn/configure
--prefix=/home/lima/vanilla_installs/gcc_and_tools --enable-__cxa_atexit
--enable-languages=c,c++ --disable-nls --disable-multilib
Thread model: posix
gcc version 4.8.0 20121223 (experimental) (GCC)
---------------------------------------------------------------