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Report information
Id: 70878
Status: open
Priority: 0/
Queue: perl5

Owner: Nobody
Requestors: frank.wiegand <frank.wiegand [at] gmail.com>
Cc:
AdminCc:

Operating System: Linux
PatchStatus: (no value)
Severity: low
Type: core
Perl Version: 5.10.1
Fixed In: (no value)



Subject: 0_ gives double warning
Date: Fri, 27 Nov 2009 15:25:24 +0100
To: perlbug [...] perl.org
From: Frank Wiegand <frank.wiegand [...] gmail.com>
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This is a bug report for perl from frank.wiegand@gmail.com, generated with the help of perlbug 1.39 running under perl 5.10.1. ----------------------------------------------------------------- % perl -we 0_ Misplaced _ in number at -e line 1. Misplaced _ in number at -e line 1. Occurs only with 0_, not 1_ or else. The doubled warning still resides in 5.11.2. Frank ----------------------------------------------------------------- --- Flags: category=core severity=low --- Site configuration information for perl 5.10.1: Configured by Debian Project at Sat Nov 7 22:18:45 UTC 2009. Summary of my perl5 (revision 5 version 10 subversion 1) configuration: Platform: osname=linux, osvers=2.6.31.5-dsa-amd64, archname=x86_64-linux-gnu-thread-multi uname='linux brahms 2.6.31.5-dsa-amd64 #1 smp fri oct 23 12:25:24 cest 2009 x86_64 gnulinux ' config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=x86_64-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.10 -Darchlib=/usr/lib/perl/5.10 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.10.1 -Dsitearch=/usr/local/lib/perl/5.10.1 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.10.1 -Dd_dosuid -des' hint=recommended, useposix=true, d_sigaction=define useithreads=define, usemultiplicity=define useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef use64bitint=define, use64bitall=define, uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2 -g', cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include' ccversion='', gccversion='4.3.4', gccosandvers='' intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16 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 -L/usr/local/lib' libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64 libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt perllibs=-ldl -lm -lpthread -lc -lcrypt libc=/lib/libc-2.10.1.so, so=so, useshrplib=true, libperl=libperl.so.5.10.1 gnulibc_version='2.10.1' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -O2 -g -L/usr/local/lib -fstack-protector' Locally applied patches: --- @INC for perl 5.10.1: /etc/perl /usr/local/lib/perl/5.10.1 /usr/local/share/perl/5.10.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl . --- Environment for perl 5.10.1: HOME=/home/fw LANG=de_DE.UTF-8 LANGUAGE= LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=/sbin:/usr/sbin:/home/fw/bin:/home/fw/bin:/usr/local/bin:/usr/bin:/bin:/usr/games PERL_AUTOINSTALL=--defaultdeps PERL_BADLANG (unset) PERL_EXTUTILS_AUTOINSTALL=--defaultdeps PERL_MM_USE_DEFAULT=1 SHELL=/bin/zsh
RT-Send-CC: perl5-porters [...] perl.org
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On Fri Nov 27 06:26:16 2009, frank.wiegand wrote: Show quoted text
> This is a bug report for perl from frank.wiegand@gmail.com, > generated with the help of perlbug 1.39 running under perl 5.10.1. > > > ----------------------------------------------------------------- > > % perl -we 0_ > Misplaced _ in number at -e line 1. > Misplaced _ in number at -e line 1. > > Occurs only with 0_, not 1_ or else. > > The doubled warning still resides in 5.11.2. > > > Frank > > -----------------------------------------------------------------
What is happening in the code: a) first it checks if the (octal) number begins with '_' b) then it checks the next charachters to see if they are valid (not the case so the parsing ends) c) then it checks if the last character was '_'. In this case there is only one character and this produces the warning (because '_' is not valid at the start of a number nor at the end of a number). The double warning also happens in the following cases: print 0x_; print 0b_; print 5._; The double warning does not happen for: print 5e_; The reason for this is that the parsing of the exponent is a bit different: a) it checks if the first character is '_' b) it checks if the second character is '+' or '-' c) it checks if the third character is _ This also means that: print 5e__-3 is parsed as: 5 - 3 (= 2) and not as 5e-3 (0.005). The only fix I can currently see is to add another var which contains the 'real start' of the number... Best regards, Bram
Subject: Re: [perl #70878] 0_ gives double warning
From: Zefram <zefram [...] fysh.org>
To: perl5-porters [...] perl.org
Date: Tue, 17 Jan 2017 00:29:12 +0000
Fixed in 72c80c749a61d30202cfa902a18be1b6f3ff6905. -zefram


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