Closed
Description
Description
Regular expression with recursive subpatterns ((?PARNO)) matches incorrectly.
Steps to Reproduce
perl -wE '"a + b + (c + d)" =~ /^((\w|\((\s)*(?1)(?3)*\))(?:(?3)*\+(?3)*(?2))*)(?3)*\+/ or die; say $1'
Expected behavior
In this regular expression, $1 is expected to match a expression-like string with balanced parenthesis, and whole pattern is to match partial expression without the last (parenthesized in this example) term (a + b +).
So this one-liner should print a + b, but actually prints a + b + (c .
Perl configuration
Summary of my perl5 (revision 5 version 33 subversion 1) configuration:
Commit id: eab86acb0400b955ce0cd22c53d66e84ec8f3b7d
Platform:
osname=linux
osvers=4.19.0-9-686-pae
archname=i686-linux
uname='linux x41 4.19.0-9-686-pae #1 smp debian 4.19.118-2+deb10u1 (2020-06-07) i686 gnulinux '
config_args='-d -Dusedevel'
hint=recommended
useposix=true
d_sigaction=define
useithreads=undef
usemultiplicity=undef
use64bitint=undef
use64bitall=undef
uselongdouble=undef
usemymalloc=n
default_inc_excludes_dot=define
Compiler:
cc='cc'
ccflags ='-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='-fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include'
ccversion=''
gccversion='8.3.0'
gccosandvers=''
intsize=4
longsize=4
ptrsize=4
doublesize=8
byteorder=1234
doublekind=3
d_longlong=define
longlongsize=8
d_longdbl=define
longdblsize=12
longdblkind=3
ivtype='long'
ivsize=4
nvtype='double'
nvsize=8
Off_t='off_t'
lseeksize=8
alignbytes=4
prototype=define
Linker and Libraries:
ld='cc'
ldflags =' -fstack-protector-strong -L/usr/local/lib'
libpth=/usr/local/lib /usr/lib/gcc/i686-linux-gnu/8/include-fixed /usr/include/i386-linux-gnu /usr/lib /lib/i386-linux-gnu /lib/../lib /usr/lib/i386-linux-gnu /usr/lib/../lib /lib /lib64 /usr/lib64
libs=-lpthread -lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
libc=libc-2.28.so
so=so
useshrplib=false
libperl=libperl.a
gnulibc_version='2.28'
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_TIMES
PERLIO_LAYERS
PERL_COPY_ON_WRITE
PERL_DONT_CREATE_GVSV
PERL_MALLOC_WRAP
PERL_OP_PARENT
PERL_PRESERVE_IVUV
PERL_USE_DEVEL
USE_LARGE_FILES
USE_LOCALE
USE_LOCALE_COLLATE
USE_LOCALE_CTYPE
USE_LOCALE_NUMERIC
USE_LOCALE_TIME
USE_PERLIO
USE_PERL_ATOF
Built under linux
Compiled at Aug 28 2020 19:07:39
@INC:
/usr/local/lib/perl5/site_perl/5.33.1/i686-linux
/usr/local/lib/perl5/site_perl/5.33.1
/usr/local/lib/perl5/5.33.1/i686-linux
/usr/local/lib/perl5/5.33.1