bug#50622: 27.2; GDB lists source code infinitely after setting a breakpoint

bug#50622: 27.2; GDB lists source code infinitely after setting a breakpoint

[Luis Sebastián Martínez Vega]

The following was executed on emacs without customizations.
First, I opened a C program, compiled it with the -g file, and ran
"gdb -i=mi lagrange -s input.c". Lagrange being the binary. I can
provide the files, but I've had this problem with any C program I try to
debug. After invoking gdb, I set a breakpoint, mainly:
b input.c:33
after setting it, I get a query in the minibuffer, asking me if I wish
to make the buffer of the current file read-only (this message is
appended in the recent messages section). After choosing either yes or
no, gdb executes the list command ad infinitum, either long enough for
emacs to hang, or until I C-d the process.


In GNU Emacs 27.2 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.27, 
cairo version 1.17.4)
of 2021-03-26 built on juergen
Windowing system distributor 'The X.Org Foundation', version 11.0.12013000
System Description: Arch Linux

Recent messages:
gud-common-init: This program is already being debugged
Quit
Target doesn’t support non-stop mode. Turning it off.
Use M-x make-directory RET RET to create the directory and its parents
error in process filter: Quit [2 times]
Bad JSON object: ",", 34
WARNING! Discarding GDB handler with token #28

The program is not being run.
File /home/luis/Documentos/LCC/5to Semestre/Análisis 
Numérico/lagrange/"/mnt/Personal/Documentos/LCC/5to 
Semestre/An\303\241lisis Num\303\251rico/lagrange/input.c" is read-only 
on disk. Make buffer read-only, too? (y or n) n

Configured using:
'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
--localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-wide-int
--with-modules --with-cairo --with-harfbuzz 'CFLAGS=-march=x86-64
-mtune=generic -O2 -pipe -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2
LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB NOTIFY
INOTIFY ACL GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD JSON
PDUMPER LCMS2 GMP

Important settings:
value of $LANG: es_MX.UTF-8
locale-coding-system: utf-8-unix

Major mode: Debugger

Minor modes in effect:
shell-dirtrack-mode: t
tooltip-mode: t
global-eldoc-mode: t
electric-indent-mode: t
mouse-wheel-mode: t
tool-bar-mode: t
menu-bar-mode: t
file-name-shadow-mode: t
global-font-lock-mode: t
font-lock-mode: t
blink-cursor-mode: t
auto-composition-mode: t
auto-encryption-mode: t
auto-compression-mode: t
line-number-mode: t
transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
format-spec rfc822 mml mml-sec password-cache epa derived epg epg-config
gnus-util rmail rmail-loaddefs text-property-search time-date mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils shell
pcomplete compile cl-seq gdb-mi bindat json subr-x map seq byte-opt gv
bytecomp byte-compile cconv gud easy-mmode comint ansi-color ring
cc-mode cc-fonts easymenu cc-guess cc-menus cc-cmds cc-styles cc-align
cc-engine cc-vars cc-defs cl-loaddefs cl-lib tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms
cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese composite charscript charprop case-table epa-hook
jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads dbusbind inotify lcms2 dynamic-setting
system-font-setting font-render-setting cairo move-toolbar gtk x-toolkit
x multi-tty make-network-process emacs)

Memory information:
((conses 16 102596 35491)
(symbols 48 10256 1)
(strings 32 27430 1617)
(string-bytes 1 995097)
(vectors 16 14964)
(vector-slots 8 186715 13270)
(floats 8 25 35)
(intervals 56 2303 203)
(buffers 1000 17))

bug#50622: 27.2; GDB lists source code infinitely after setting a breakpoint

[Eli Zaretskii]

> Date: Thu, 16 Sep 2021 01:36:10 -0500
> From: Luis Sebastián Martínez Vega
>  <sebastian-440@live.com>
> 
> The following was executed on emacs without customizations.
> First, I opened a C program, compiled it with the -g file, and ran
> "gdb -i=mi lagrange -s input.c". Lagrange being the binary. I can
> provide the files, but I've had this problem with any C program I try to
> debug. After invoking gdb, I set a breakpoint, mainly:
> b input.c:33
> after setting it, I get a query in the minibuffer, asking me if I wish
> to make the buffer of the current file read-only (this message is
> appended in the recent messages section). After choosing either yes or
> no, gdb executes the list command ad infinitum, either long enough for
> emacs to hang, or until I C-d the process.

I think this is due to non-ASCII characters in your file names, as
evidenced by this:

> error in process filter: Quit [2 times]
> Bad JSON object: ",", 34
> WARNING! Discarding GDB handler with token #28
> 
> The program is not being run.
> File /home/luis/Documentos/LCC/5to Semestre/Análisis 
> Numérico/lagrange/"/mnt/Personal/Documentos/LCC/5to 
> Semestre/An\303\241lisis Num\303\251rico/lagrange/input.c" is read-only 
> on disk. Make buffer read-only, too? (y or n) n

Does it help to set gdb-mi-decode-strings to 'utf-8'?

If this doesn't help, would it be feasible for you to try the current
master branch of the Emacs Git repository?  I think this issue got a
thorough treatment there.

bug#50622: 27.2; GDB lists source code infinitely after setting a breakpoint

[Eli Zaretskii]

> Date: Thu, 16 Sep 2021 21:12:54 -0500
> From: Luis Sebastián Martínez Vega
>  <sebastian-440@live.com>
> 
> Thanks for the fast response.
> 
> Looks like setting gdb-mi-decode-strings to utf-8 made the trick.

Thanks.  I'm therefore closing this bug.  If you bump into a situation
where gdb-mi-decode-strings doesn't help, please write to the same bug
address, 50622@debbugs.gnu.org, and we will reopen the discussion.