[Bug c++/71058] New: ICE when building heavy templating and -std=c++17 -gstabs

["vapier at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71058

            Bug ID: 71058
           Summary: ICE when building heavy templating and -std=c++17
                    -gstabs
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vapier at gcc dot gnu.org
                CC: toolchain at gentoo dot org
  Target Milestone: ---
            Target: x86_64-linux-gnu

when compiling this small test case, gcc-5+ crashes.  not a regression since it
requires -std=c++17 which is new to gcc-5.

$ cat test.ii
enum VkPipelineBindPoint {};
template <typename> struct A;
template <VkPipelineBindPoint> struct B;
template <> struct A<int> {
  template <VkPipelineBindPoint P> static auto a = B<P>::func;
};

$ g++-5.3.0 -c test.ii -gstabs -std=c++17
test.ii:4:20: internal compiler error: Segmentation fault
 template <> struct A<int> {
                    ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.gentoo.org/> for instructions.

$ gdb --args g++-5.3.0 -c test.ii -gstabs -std=c++17
(gdb) set follow-fork-mode child
(gdb) run
Starting program: /usr/bin/g++-5.3.0 -c test.ii -gstabs -std=c++17
[New process 25621]
process 25621 is executing new program:
/usr/libexec/gcc/x86_64-pc-linux-gnu/5.3.0/cc1plus

Thread 2.1 "cc1plus" received signal SIGSEGV, Segmentation fault.
[Switching to process 25621]
0x0000000000d071a3 in safe_uhwi (val=val@entry=0x7ffff68a13f8,
len=len@entry=0x0, i=<optimized out>) at .../gcc-5.3.0/gcc/wide-int.cc:85
85      .../gcc-5.3.0/gcc/wide-int.cc: No such file or directory.
(gdb) bt
#0  0x0000000000d071a3 in safe_uhwi (val=val@entry=0x7ffff68a13f8,
len=len@entry=0x0, i=<optimized out>) at .../gcc-5.3.0/gcc/wide-int.cc:85
#1  0x0000000000d09cb3 in safe_uhwi (i=<optimized out>, len=0x0,
val=0x7ffff68a13f8) at .../gcc-5.3.0/gcc/wide-int.cc:85
#2  wi::lshift_large (val=val@entry=0x7fffffffc250, xval=0x7ffff68a13f8,
xlen=0x0, precision=precision@entry=0x80, shift=shift@entry=0x3) at
.../gcc-5.3.0/gcc/wide-int.cc:1917
#3  0x00000000007eae41 in wi::lshift<generic_wide_int<wi::extended_tree<128> >,
int> (y=<optimized out>, x=...) at .../gcc-5.3.0/gcc/wide-int.h:2860
#4  int_bit_position (field=0x7ffff68a0280, field=0x7ffff68a0280) at
.../gcc-5.3.0/gcc/tree.h:5079
#5  dbxout_type_fields (type=<optimized out>) at
.../gcc-5.3.0/gcc/dbxout.c:1546
#6  dbxout_type (type=<optimized out>, type@entry=0x7ffff689ec78,
full=<optimized out>, full@entry=0x1) at .../gcc-5.3.0/gcc/dbxout.c:2223
#7  0x00000000007ed437 in dbxout_symbol (decl=0x7ffff689a720, local=<optimized
out>) at .../gcc-5.3.0/gcc/dbxout.c:2795
#8  0x0000000000a33d56 in rest_of_type_compilation
(type=type@entry=0x7ffff689ec78, toplev=0x1) at .../gcc-5.3.0/gcc/passes.c:309
#9  0x0000000000663b50 in finish_struct_1 (t=0x7ffff689ec78) at
.../gcc-5.3.0/gcc/cp/class.c:6742
#10 0x000000000066484d in finish_struct (t=t@entry=0x7ffff689ec78,
attributes=0x0) at .../gcc-5.3.0/gcc/cp/class.c:6908
#11 0x0000000000682506 in cp_parser_class_specifier_1 (parser=0x7ffff68a0000)
at .../gcc-5.3.0/gcc/cp/parser.c:19880
#12 cp_parser_class_specifier (parser=0x7ffff68a0000) at
.../gcc-5.3.0/gcc/cp/parser.c:20108  
#13 cp_parser_type_specifier (parser=parser@entry=0x7ffff68a0000,
flags=flags@entry=0x1, decl_specs=decl_specs@entry=0x7fffffffc6f0,
is_declaration=is_declaration@entry=0x1,
declares_class_or_enum=declares_class_or_enum@entry=0x7fffffffc684,
is_cv_qualifier=is_cv_qualifier@entry=0x7fffffffc683) at
.../gcc-5.3.0/gcc/cp/parser.c:14727  
#14 0x0000000000697de0 in cp_parser_decl_specifier_seq
(parser=parser@entry=0x7ffff68a0000, flags=flags@entry=0x1,
decl_specs=decl_specs@entry=0x7fffffffc6f0,
declares_class_or_enum=declares_class_or_enum@entry=0x7fffffffc6ec) at
.../gcc-5.3.0/gcc/cp/parser.c:11958  
#15 0x000000000069ceed in cp_parser_single_declaration
(parser=parser@entry=0x7ffff68a0000, checks=checks@entry=0x0,
member_p=member_p@entry=0x0,
explicit_specialization_p=explicit_specialization_p@entry=0x1,
friend_p=friend_p@entry=0x0) at .../gcc-5.3.0/gcc/cp/parser.c:23776
#16 0x000000000069d8a9 in cp_parser_explicit_specialization
(parser=parser@entry=0x7ffff68a0000) at .../gcc-5.3.0/gcc/cp/parser.c:14623
#17 0x000000000067f9b0 in cp_parser_declaration
(parser=parser@entry=0x7ffff68a0000) at .../gcc-5.3.0/gcc/cp/parser.c:11332
#18 0x00000000006a703b in cp_parser_declaration_seq_opt
(parser=parser@entry=0x7ffff68a0000) at .../gcc-5.3.0/gcc/cp/parser.c:11265
#19 0x00000000006a7392 in cp_parser_translation_unit (parser=0x7ffff68a0000) at
.../gcc-5.3.0/gcc/cp/parser.c:4100
#20 c_parse_file () at .../gcc-5.3.0/gcc/cp/parser.c:33229
#21 0x000000000075f0ba in c_common_parse_file () at
.../gcc-5.3.0/gcc/c-family/c-opts.c:1057
#22 0x0000000000ae1331 in compile_file () at .../gcc-5.3.0/gcc/toplev.c:594
#23 0x00000000005e7cb0 in do_compile () at .../gcc-5.3.0/gcc/toplev.c:2067
#24 toplev::main (this=this@entry=0x7fffffffc920, argc=argc@entry=0xf,
argv=argv@entry=0x7fffffffca28) at .../gcc-5.3.0/gcc/toplev.c:2165
#25 0x00000000005e8a1e in main (argc=0xf, argv=0x7fffffffca28) at
.../gcc-5.3.0/gcc/main.c:39