Bug #20979: +comment does not affect parsetree without `--parser=parse.y`

• Status: Closed
• Assignee: -
• Target version: 3.4
• ruby -v: ruby 3.4.0dev (2024-12-23T02:52:14Z master b19fcd02fa) +PRISM [arm64-darwin24]
• Backport: 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED

[znz (Kazuhiro NISHIYAMA)]

ruby --help says +comment Add comments to AST (affects parsetree)., but it does not affect without --parser=parse.y.

If it is intentional, I think it needs more help messages or more explanation somewhere.
 

Dump List:
  insns           Instruction sequences.
  yydebug         yydebug of yacc parser generator.
  parsetree       Abstract syntax tree (AST).
  -optimize       Disable optimization (affects insns).
  +error-tolerant Error-tolerant parsing (affects yydebug, parsetree).
  +comment        Add comments to AST (affects parsetree).

% git diff --no-index --stat =(ruby --dump=parsetree -e 0) =(ruby --dump=parsetree+comment -e 0)
% git diff --no-index --stat =(ruby --parser=parse.y --dump=parsetree -e 0) =(ruby --parser=parse.y --dump=parsetree+comment -e 0)
 /tmp/{zshEGciGv => zshWgqfVT} | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

[znz (Kazuhiro NISHIYAMA)]

• Description updated (diff)

[nobu (Nobuyoshi Nakada)]

• Backport changed from 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN to 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED

https://github.com/ruby/ruby/pull/12450

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|1b0c46daed9186b82ab4fef1a4ab225afe582ee6.

---

[Bug #20979] [DOC] Add a proviso to +comment option