From: ibylich@... Date: 2018-04-17T01:27:43+00:00 Subject: [ruby-core:86555] [Ruby trunk Bug#14690] Invalid CMDARG state after command_args followed by tLBRACE_ARG Issue #14690 has been updated by ibylich (Ilya Bylich). Thank you! ---------------------------------------- Bug #14690: Invalid CMDARG state after command_args followed by tLBRACE_ARG https://bugs.ruby-lang.org/issues/14690#change-71496 * Author: ibylich (Ilya Bylich) * Status: Closed * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.6.0dev (2018-04-15 trunk 63161) [x86_64-darwin17] * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN ---------------------------------------- ~~~ ruby assert_valid_syntax('let () { m(a) do; end }') ~~~ The patch that fixes it is attached. tLBRACE_ARG does "CMDARG_PUSH(0)" in the lexer and then the parser leaves the "command_args" rule. The parser does "CMDARG_POP" to remove 1 from the top of the "CMDARG", but the thing here is that there's a 0 on top (the one pushed by tLBRACE_ARG) and the parser pops a wrong value. If the next token is tLBRACE_ARG the parser should pop 2nd top value (like "tmp = pop; pop; push(tmp)"). From what I understand that's the only token that can mutate "CMDARG" in the lexer and that can be emitted after command args. I've found it during stress-testing a parser gem and that's the only issue that I was able to find so far. ---Files-------------------------------- cmdarg_in_command_args_followed_by_tlbrace_arg.patch (1.18 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: