Subject: bug#75498: closed (Re: bug#75498: 31.0.50; cl-block is not lexically scoped)

From: [email-masked] (GNU bug Tracking System)
Date: Thu, 16 Jan 2025 22:50:01 +0000

Your bug report

#75498: 31.0.50; cl-block is not lexically scoped

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
75498: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=75498
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#75498: 31.0.50; cl-block is not lexically scoped
From: Stefan Monnier <[email-masked]>
To: Michael Heerdegen <[email-masked]>
Cc: [email-masked], [email-masked], [email-masked]
Date: Thu, 16 Jan 2025 17:48:59 -0500
List-Id: <debbugs-submit.debbugs.gnu.org>

>> Has somebody recompiled Emacs with the patch installed and looked for
>> such new compiler warnings?
> I just checked: there are no new compiler warnings when the patch is
> installed.

Thanks, pushed to `master`.

        Stefan

Subject: 31.0.50; cl-block is not lexically scoped
From: Ihor Radchenko <[email-masked]>
To: [email-masked]
Date: Sat, 11 Jan 2025 16:10:39 +0000
List-Id: <debbugs-submit.debbugs.gnu.org>

According to the docstring, `cl-block' should be lexically scoped:

    Code inside the BODY forms can call cl-return-from
    to jump prematurely out of the block.  This differs from catch and throw
    in two respects:  First, the NAME is an unevaluated symbol rather than a
    quoted symbol or other form; and second, NAME is lexically rather than
    dynamically scoped:  Only references to it within BODY will work.  These
    references may appear inside macro expansions, but not inside functions
    called from BODY.

But try the following reproducer:

1. create file test.el

;; -*- lexical-binding: t; -*-

(defun return-from-x ()
  (cl-return-from x 'dynamic))

(defun x-block ()
  (cl-block x
    (return-from-x)
    (cl-return-from x 'lexical)))

2. (load "/path/to/test.el)
3. M-: (x-block)

Expected: 'lexical is returned.
Observed: 'dynamic is returned.

In GNU Emacs 31.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.42, cairo version 1.18.2) of 2025-01-10 built on localhost
Repository revision: e8deac66adef279a15c806d7547a7610b0189795
Repository branch: scratch/igc
Windowing system distributor 'The X.Org Foundation', version 11.0.12101014
System Description: Gentoo Linux

Configured using:
 'configure --with-mps=yes --with-native-compilation 'CFLAGS=-g3
 -I/opt/mps/include -L/opt/mps/lib'
 JAVAC=/etc/java-config-2/current-system-vm/bin/javac
 PKG_CONFIG_PATH=/usr/share/guile-data/3.0/pkgconfig'

-- 
Ihor Radchenko // yantar92,
Org mode maintainer,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>