Bug #20926: shareable_constant_value: experimental_everything crashes with parse.y

• Status: Open
• Assignee: -
• Target version: -
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[tenderlovemaking (Aaron Patterson)]

This program crashes with parse.y as the parser:

./miniruby --dump=insns --parser=parse.y -v -e'# shareable_constant_value: experimental_everything
                                          C = { **{ } }'

Backtrace from LLDB looks like this:

(lldb) run
Process 66489 launched: '/Users/aaron/git/ruby/miniruby' (arm64)
Process 66489 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x3523922faa9c0058)
    frame #0: 0x0000000100220f84 miniruby`RB_BUILTIN_TYPE(obj=3829064841618522200) at value_type.h:191:30
   188 	     * RB_SPECIAL_CONST_P check. */
   189 	    __asm volatile("": : :"memory");
   190 	#endif
-> 191 	    VALUE ret = RBASIC(obj)->flags & RUBY_T_MASK;
   192 	    return RBIMPL_CAST((enum ruby_value_type)ret);
   193 	}
   194 	
Target 0: (miniruby) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x3523922faa9c0058)
  * frame #0: 0x0000000100220f84 miniruby`RB_BUILTIN_TYPE(obj=3829064841618522200) at value_type.h:191:30
    frame #1: 0x0000000100220e84 miniruby`RCLASS_SINGLETON_P [inlined] rbimpl_RB_TYPE_P_fastpath(obj=3829064841618522200, t=RUBY_T_CLASS) at value_type.h:352:19
    frame #2: 0x0000000100220d0c miniruby`RCLASS_SINGLETON_P(klass=3829064841618522200) at class.h:202:12
    frame #3: 0x0000000100220c80 miniruby`rb_class_real(cl=3829064841618522200) at object.c:290:10
    frame #4: 0x0000000100220fd8 miniruby`rb_obj_class(obj=6171908688) at object.c:299:12
    frame #5: 0x0000000100172218 miniruby`rb_hash_aset(hash=4367092992, key=6171908688, val=4367092800) at hash.c:2931:10
    frame #6: 0x0000000100090a1c miniruby`compile_shareable_literal_constant(iseq=0x00000001043e10d0, ret=0x000000016fdfdad8, shareable=rb_parser_shareable_everything, dest=0x000000014c7c5468, node=0x000000014c7c5548, level=0, value_p=0x000000016fdfdac8, shareable_literal_p=0x000000016fdfdad4) at compile.c:10507:21
    frame #7: 0x000000010007db5c miniruby`compile_shareable_constant_value(iseq=0x00000001043e10d0, ret=0x000000016fdfe518, shareable=rb_parser_shareable_everything, lhs=0x000000014c7c5468, value=0x000000014c7c5548) at compile.c:10591:9
    frame #8: 0x0000000100073e10 miniruby`iseq_compile_each0(iseq=0x00000001043e10d0, ret=0x000000016fdfe518, node=0x000000014c7c5468, popped=0) at compile.c:10786:13
    frame #9: 0x0000000100057354 miniruby`iseq_compile_each(iseq=0x00000001043e10d0, ret=0x000000016fdfe518, node=0x000000014c7c5468, popped=0) at compile.c:10624:12
    frame #10: 0x0000000100056f0c miniruby`rb_iseq_compile_node(iseq=0x00000001043e10d0, node=0x000000014c7c5578) at compile.c:919:13
    frame #11: 0x00000001001b8cbc miniruby`rb_iseq_new_with_opt(ast_value=4366143936, name=4343347824, path=4343499984, realpath=4366954464, first_lineno=0, parent=0x0000000102e23a40, isolated_depth=0, type=ISEQ_TYPE_MAIN, option=0x000000016fdfe648, script_lines=4) at iseq.c:1011:5
    frame #12: 0x00000001001b9230 miniruby`rb_iseq_new_main(ast_value=4366143936, path=4343499984, realpath=4366954464, parent=0x0000000102e23a40, opt=1) at iseq.c:915:12
    frame #13: 0x000000010031715c miniruby`process_options(argc=0, argv=0x000000016fdff5d8, opt=0x000000016fdff0e0) at ruby.c:2627:20
    frame #14: 0x0000000100316000 miniruby`ruby_process_options(argc=3, argv=0x000000016fdff5c0) at ruby.c:3169:12
    frame #15: 0x00000001001260a8 miniruby`ruby_options(argc=3, argv=0x000000016fdff5c0) at eval.c:117:16
    frame #16: 0x0000000100001940 miniruby`rb_main(argc=3, argv=0x000000016fdff5c0) at main.c:43:26
    frame #17: 0x00000001000018cc miniruby`main(argc=3, argv=0x000000016fdff5c0) at main.c:68:12
    frame #18: 0x0000000199240274 dyld`start + 2840

I think the program is supposed to emit instructions that look like this:

$ ruby -v --dump=insns test.rb
ruby 3.3.4 (2024-07-16 revision 425e468d25) [arm64-darwin23]
== disasm: #<ISeq:<main>@test.rb:1 (1,0)-(3,13)>
0000 putobject                              {nil=>{}}                 (   3)[Li]
0002 dup
0003 putspecialobject                       3
0005 setconstant                            :C
0007 leave

[tenderlovemaking (Aaron Patterson)]

• Related to Bug #20927: `{ **{ } }` behaves differently when `shareable_constant_value: experimental_everything` added