B::Concise doesn't entirely honour walk_output() #24024
Description
Module: B::Concise
Description
Besides the use via -MO, B::Concise has an API which can be used from runtime code to dump op trees with a bit more control.
This includes a function walk_output() which is meant to set the output of the dump.
One function writes to the wrong place.
Steps to Reproduce
~/perl/v5.42.0-threads/bin/perl -mB::Concise -e 'sub f { return shift; } my $buf; B::Concise::walk_output(\$buf) or die; my $w = B::Concise::compile("-concise", "-stash=main"); $w->(); $buf =~ s/^/ > /gm; print $buf'
FUNC: *main::f
> 3 <1> leavesub[1 ref] K/REFC,1 ->(end)
> - <@> lineseq KP ->3
> 1 <;> nextstate(main -8 -e:1) v ->2
> - <@> return K ->-
> - <0> pushmark s ->2
> 2 <0> shift s* ->3
> y <@> leave[1 ref] vKP/REFC ->(end)
> 4 <0> enter v ->5
> 5 <;> nextstate(main -7 -e:1) v:{ ->6
> 6 <0> padsv[$buf:-7,-5] vM/LVINTRO ->7
> 7 <;> nextstate(main -6 -e:1) v:{ ->8
...
Note that the FUNC: *main::fline isn't captured in $buf
Expected behavior
All of the output, including the FUNC: *main::f line is written to $buf
Perl configuration
Summary of my perl5 (revision 5 version 42 subversion 0) configuration:
Platform:
osname=linux
osvers=6.12.43+deb13-amd64
archname=x86_64-linux-thread-multi
uname='linux ares 6.12.43+deb13-amd64 #1 smp preempt_dynamic debian 6.12.43-1 (2025-08-27) x86_64 gnulinux '
config_args='-des -Dprefix=/home/tony/perl/v5.42.0-threads -Accflags=-march=native -Dusethreads'
hint=recommended
useposix=true
d_sigaction=define
useithreads=define
usemultiplicity=define
use64bitint=define
use64bitall=define
uselongdouble=undef
usemymalloc=n
default_inc_excludes_dot=define
Compiler:
cc='cc'
ccflags ='-D_REENTRANT -D_GNU_SOURCE -march=native -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2'
optimize='-O2'
cppflags='-D_REENTRANT -D_GNU_SOURCE -march=native -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
ccversion=''
gccversion='14.2.0'
gccosandvers=''
intsize=4
longsize=8
ptrsize=8
doublesize=8
byteorder=12345678
doublekind=3
d_longlong=define
longlongsize=8
d_longdbl=define
longdblsize=16
longdblkind=3
ivtype='long'
ivsize=8
nvtype='double'
nvsize=8
Off_t='off_t'
lseeksize=8
alignbytes=8
prototype=define
Linker and Libraries:
ld='cc'
ldflags =' -fstack-protector-strong -L/usr/local/lib'
libpth=/usr/local/lib /usr/lib/x86_64-linux-gnu /usr/lib /usr/lib64
libs=-lpthread -ldl -lm -lcrypt -lutil -lc
perllibs=-lpthread -ldl -lm -lcrypt -lutil -lc
libc=/lib/x86_64-linux-gnu/libc.so.6
so=so
useshrplib=false
libperl=libperl.a
gnulibc_version='2.41'
Dynamic Linking:
dlsrc=dl_dlopen.xs
dlext=so
d_dlsymun=undef
ccdlflags='-Wl,-E'
cccdlflags='-fPIC'
lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector-strong'
Characteristics of this binary (from libperl):
Compile-time options:
HAS_LONG_DOUBLE
HAS_STRTOLD
HAS_TIMES
MULTIPLICITY
PERLIO_LAYERS
PERL_COPY_ON_WRITE
PERL_DONT_CREATE_GVSV
PERL_HASH_FUNC_SIPHASH13
PERL_HASH_USE_SBOX32
PERL_MALLOC_WRAP
PERL_OP_PARENT
PERL_PRESERVE_IVUV
PERL_USE_SAFE_PUTENV
USE_64_BIT_ALL
USE_64_BIT_INT
USE_ITHREADS
USE_LARGE_FILES
USE_LOCALE
USE_LOCALE_COLLATE
USE_LOCALE_CTYPE
USE_LOCALE_NUMERIC
USE_LOCALE_TIME
USE_PERLIO
USE_PERL_ATOF
USE_REENTRANT_API
USE_THREAD_SAFE_LOCALE
Built under linux
Compiled at Dec 18 2025 20:40:39
@INC:
/home/tony/perl/v5.42.0-threads/lib/site_perl/5.42.0/x86_64-linux-thread-multi
/home/tony/perl/v5.42.0-threads/lib/site_perl/5.42.0
/home/tony/perl/v5.42.0-threads/lib/5.42.0/x86_64-linux-thread-multi
/home/tony/perl/v5.42.0-threads/lib/5.42.0