Issue #20916 has been updated by tenderlovemaking (Aaron Patterson). I created a bug for the parse.y version here: https://bugs.ruby-lang.org/issues/20926 The example @mame provides works on Ruby 3.3. I think it's supposed to emit instructions 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 ``` Note that if you remove the comment the iseqs 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)-(2,13)> 0000 newhash 0 ( 2)[Li] 0002 dup 0003 putspecialobject 3 0005 setconstant :C 0007 leave ``` I think the main difference is the `putobject` instruction. ---------------------------------------- Bug #20916: Prism compiler should support ** in Ractor constant https://bugs.ruby-lang.org/issues/20916#change-110823 * Author: mame (Yusuke Endoh) * Status: Open * Assignee: prism * ruby -v: ruby 3.4.0dev (2024-11-28T02:34:20Z avoid-uninitialize.. 79ae6e72c8) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- The Prism compiler raises an exception against the following code. ``` $ ./miniruby -e '# shareable_constant_value: experimental_everything C = { **{ } }' -e:2: Ractor constant writes do not support ** -e: node type not implemented (NotImplementedError) ``` But the traditional compiler support it, and @ko1 said it should be supported. Also, I feel that this error message `node type not implemented` is a sign of a worse problem. Actually, valgrind reports `Conditional jump or move depends on uninitialised value(s)`against the Prism compiler. An assertion failure is also reported. ``` $ valgrind ./miniruby -e '# shareable_constant_value: experimental_everything C = { **{ } }' ==49978== Memcheck, a memory error detector ==49978== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al. ==49978== Using Valgrind-3.22.0 and LibVEX; rerun with -h for copyright info ==49978== Command: ./miniruby -e #\ shareable_constant_value:\ experimental_everything_C\ =\ {\ **{\ }\ } ==49978== ==49978== Warning: set address range perms: large range [0x64e0000, 0x1e4e0000) (defined) -e:2: Ractor constant writes do not support ** ==49978== Conditional jump or move depends on uninitialised value(s) ==49978== at 0x4BB42A: pm_newline_list_line (pm_newline_list.c:63) ==49978== by 0x1E718A: pm_compile_shareable_constant_value (prism_compile.c:5280) ==49978== by 0x1E7243: pm_compile_shareable_constant_value (prism_compile.c:5318) ==49978== by 0x1E8DC1: pm_compile_constant_write_node.isra.0 (prism_compile.c:5372) ==49978== by 0x1DCB2F: pm_compile_node (prism_compile.c:9823) ==49978== by 0x1DC9C8: pm_compile_node (prism_compile.c:9934) ==49978== by 0x1F3AC9: pm_compile_scope_node.isra.0 (prism_compile.c:6603) ==49978== by 0x1DA66A: pm_compile_node (prism_compile.c:9805) ==49978== by 0x1F61A7: pm_iseq_compile_node (prism_compile.c:10109) ==49978== by 0x2A5303: pm_iseq_new_with_opt_try (iseq.c:1027) ==49978== by 0x23DFF2: rb_protect (eval.c:1033) ==49978== by 0x2AB198: pm_iseq_new_with_opt (iseq.c:1080) ==49978== miniruby: prism/util/pm_newline_list.c:63: pm_newline_list_line: Assertion `cursor >= list->start' failed. ==49978== ==49978== Process terminating with default action of signal 6 (SIGABRT) ==49978== at 0x4AFAB1C: __pthread_kill_implementation (pthread_kill.c:44) ==49978== by 0x4AFAB1C: __pthread_kill_internal (pthread_kill.c:78) ==49978== by 0x4AFAB1C: pthread_kill@@GLIBC_2.34 (pthread_kill.c:89) ==49978== by 0x4AA126D: raise (raise.c:26) ==49978== by 0x4A848FE: abort (abort.c:79) ==49978== by 0x4A8481A: __assert_fail_base.cold (assert.c:94) ==49978== by 0x4A97506: __assert_fail (assert.c:103) ==49978== by 0x4BB49B: pm_newline_list_line (pm_newline_list.c:63) ==49978== by 0x1E718A: pm_compile_shareable_constant_value (prism_compile.c:5280) ==49978== by 0x1E7243: pm_compile_shareable_constant_value (prism_compile.c:5318) ==49978== by 0x1E8DC1: pm_compile_constant_write_node.isra.0 (prism_compile.c:5372) ==49978== by 0x1DCB2F: pm_compile_node (prism_compile.c:9823) ==49978== by 0x1DC9C8: pm_compile_node (prism_compile.c:9934) ==49978== by 0x1F3AC9: pm_compile_scope_node.isra.0 (prism_compile.c:6603) ==49978== ==49978== HEAP SUMMARY: ==49978== in use at exit: 2,645,494 bytes in 10,084 blocks ==49978== total heap usage: 36,662 allocs, 26,578 frees, 6,066,537 bytes allocated ==49978== ==49978== LEAK SUMMARY: ==49978== definitely lost: 0 bytes in 0 blocks ==49978== indirectly lost: 0 bytes in 0 blocks ==49978== possibly lost: 1,050,576 bytes in 4 blocks ==49978== still reachable: 1,594,918 bytes in 10,080 blocks ==49978== suppressed: 0 bytes in 0 blocks ==49978== Rerun with --leak-check=full to see details of leaked memory ==49978== ==49978== Use --track-origins=yes to see where uninitialised values come from ==49978== For lists of detected and suppressed errors, rerun with: -s ==49978== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) Aborted (core dumped) ``` -- https://bugs.ruby-lang.org/