Issue #19862 has been reported by yui-knk (Kaneko Yuichiro). ---------------------------------------- Bug #19862: argument stack underflow compile error happens for the combination of and/or & one line pattern matching https://bugs.ruby-lang.org/issues/19862 * Author: yui-knk (Kaneko Yuichiro) * Status: Open * Priority: Normal * ruby -v: ruby 3.3.0dev (2023-09-04T18:01:33Z master db3b814cb0) [arm64-darwin21] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- This code raises argument stack underflow compile error on ruby 3.3 which is under development. ```ruby # test3.rb if true or {a: 0} in {a:} p 1 else p 0 end ``` ```shell % ruby -v test3.rb ruby 3.3.0preview1 (2023-05-12 master a1b01e7701) [arm64-darwin21] test3.rb:2: warning: assigned but unused variable - a -- raw disasm-------- trace: 1 0000 jump <L000> ( 2) <L006> [sp: 0] <L004> [sp: 0] * 0002 pop ( 2) 0003 pop ( 2) 0004 jump <L001> ( 2) <L000> [sp: 0] trace: 1 0006 putself ( 3) 0007 putobject_INT2FIX_1_ ( 3) 0008 opt_send_without_block <calldata:p, 1> ( 3) 0010 leave ( 5) <L001> [sp: -1] trace: 1 0011 putself ( 5) 0012 putobject_INT2FIX_0_ ( 5) 0013 opt_send_without_block <calldata:p, 1> ( 5) 0015 leave ( 5) --------------------- test3.rb:2: argument stack underflow (-1) test3.rb: compile error (SyntaxError) % ./ruby -v ../../test3.rb ruby 3.3.0dev (2023-09-04T18:01:33Z master db3b814cb0) [arm64-darwin21] `RubyGems' were not loaded. `error_highlight' was not loaded. `did_you_mean' was not loaded. `syntax_suggest' was not loaded. ../../test3.rb:2: warning: assigned but unused variable - a -- raw disasm-------- trace: 1 0000 jump <L000> ( 2) <L006> [sp: 0] <L004> [sp: 0] * 0002 pop ( 2) 0003 pop ( 2) 0004 jump <L001> ( 2) <L000> [sp: 0] trace: 1 0006 putself ( 3) 0007 putobject_INT2FIX_1_ ( 3) 0008 opt_send_without_block <calldata:p, 1> ( 3) 0010 leave ( 5) <L001> [sp: -1] trace: 1 0011 putself ( 5) 0012 putobject_INT2FIX_0_ ( 5) 0013 opt_send_without_block <calldata:p, 1> ( 5) 0015 leave ( 5) --------------------- ../../test3.rb:2: argument stack underflow (-1) ../../test3.rb: compile error (SyntaxError) ``` This also raises same error. ```ruby # test4.rb if false and {a: 0} in {a:} p 1 else p 0 end ``` As far as I checked, 3.0.0, 3.1.0, 3.2.0 don't raise the error. -- https://bugs.ruby-lang.org/