when(scalar){} -> S_looks_like_bool: Assertion `o' failed.

[p5pRT]

Migrated from rt.perl.org#74114 (status was 'resolved')

Searchable as RT74114$

[p5pRT]

From frank.wiegand@gmail.com

This is a bug report for perl from frank.wiegand@​gmail.com,
generated with the help of perlbug 1.39 running under perl 5.12.0.

---

  % perl-5.10.1 -E 'when(scalar){}'
  Not enough arguments for scalar at -e line 1, near "scalar)"
  Execution of -e aborted due to compilation errors.

  % perl-5.12.0-RC3 -E 'when(scalar){}'
  perl-5.12.0-RC3​: op.c​:5272​: S_looks_like_bool​: Assertion `o' failed.
  Aborted

This regression has been introduced by the following commit (as git
bisect says)​:

5341b2b is the first bad commit
commit 5341b2b
Author​: Josh ben Jore <jjore@​cpan.org>
Date​: Wed Sep 23 15​:35​:14 2009 -0700

  Fix when( scalar ... ) bug

  looks_like_bool should look past scalar(). Prior to this fix, saying
  scalar() caused the when() argument to be /not/ a boolean even if it
  reasonably was. Perhaps something like​: when( scalar /$re/ ). I don't
  know any natural way someone is doing to use when(scalar ...) but it
  certainly seems like it was mistakenly left out.

:100644 100644 729c25f0aa87bcd25f8606bd70d852c6c67e1967 c3736fac0b76b2e4beaf755d5a628d4d71e129d3 M op.c
:040000 040000 afe81091570f36d8e50f3513ec91f3f0f27b55f4 03acff2025d490e42f74d28599f1df3994becef1 M t

Thanks, Frank

---

---

Flags​:
  category=core
  severity=low

---

Site configuration information for perl 5.12.0​:

Configured by fw at Sat Apr 3 09​:18​:00 CEST 2010.

Summary of my perl5 (revision 5 version 12 subversion 0) configuration​:
 
  Platform​:
  osname=linux, osvers=2.6.32-trunk-amd64, archname=x86_64-linux
  uname='linux hal2 2.6.32-trunk-amd64 #1 smp sun jan 10 22​:40​:40 utc 2010 x86_64 gnulinux '
  config_args='-de -Dusedevel -DDEBUGGING=both -Doptimize=-g -Dcc=ccache gcc -Dld=gcc -Dprefix=/opt/perl/perl-5.12.0-RC3/ -Dmad'
  hint=recommended, useposix=true, d_sigaction=define
  useithreads=undef, usemultiplicity=undef
  useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
  use64bitint=define, use64bitall=define, uselongdouble=undef
  usemymalloc=n, bincompat5005=undef
  Compiler​:
  cc='ccache gcc', ccflags ='-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
  optimize='-g',
  cppflags='-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
  ccversion='', gccversion='4.4.3 20100108 (prerelease)', 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='gcc', ldflags =' -fstack-protector -L/usr/local/lib'
  libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64
  libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
  perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
  libc=/lib/libc-2.10.2.so, so=so, useshrplib=false, libperl=libperl.a
  gnulibc_version='2.10.2'
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
  cccdlflags='-fPIC', lddlflags='-shared -g -L/usr/local/lib -fstack-protector'

Locally applied patches​:
  RC3

---

@​INC for perl 5.12.0​:
  /opt/perl/perl-5.12.0-RC3/lib/site_perl/5.12.0/x86_64-linux
  /opt/perl/perl-5.12.0-RC3/lib/site_perl/5.12.0
  /opt/perl/perl-5.12.0-RC3/lib/5.12.0/x86_64-linux
  /opt/perl/perl-5.12.0-RC3/lib/5.12.0
  .

---

Environment for perl 5.12.0​:
  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

[p5pRT]

From @rgarcia

On 7 April 2010 13​:36, Frank Wiegand <perlbug-followup@​perl.org> wrote​:

 % perl-5.10.1 -E 'when(scalar){}'
 Not enough arguments for scalar at -e line 1, near "scalar)"
 Execution of -e aborted due to compilation errors.

 % perl-5.12.0-RC3 -E 'when(scalar){}'
 perl-5.12.0-RC3​: op.c​:5272​: S_looks_like_bool​: Assertion `o' failed.
 Aborted

Thanks for the report and the bisect !

Here's a patch that makes it report a syntax error instead. I'll apply
to maint 5.12 when opened.

Inline Patch

diff --git a/op.c b/op.c
index 9c94cc8..76eb16f 100644
--- a/op.c
+++ b/op.c
@@ -5282,14 +5282,11 @@ S_looks_like_bool(pTHX_ const OP *o)
             && looks_like_bool(cLOGOPo->op_first->op_sibling));

        case OP_NULL:
+       case OP_SCALAR:
            return (
                o->op_flags & OPf_KIDS
            && looks_like_bool(cUNOPo->op_first));

-        case OP_SCALAR:
-            return looks_like_bool(cUNOPo->op_first);
-
-
        case OP_ENTERSUB:

        case OP_NOT:    case OP_XOR:

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From @obra

On Fri Apr 09 03​:25​:49 2010, rgs@​consttype.org wrote​:

On 7 April 2010 13​:36, Frank Wiegand <perlbug-followup@​perl.org> wrote​:

 % perl-5.10.1 -E 'when(scalar){}'
 Not enough arguments for scalar at -e line 1, near "scalar)"
 Execution of -e aborted due to compilation errors.

 % perl-5.12.0-RC3 -E 'when(scalar){}'
 perl-5.12.0-RC3​: op.c​:5272​: S_looks_like_bool​: Assertion `o' failed.
 Aborted

Thanks for the report and the bisect !

Here's a patch that makes it report a syntax error instead. I'll apply
to maint 5.12 when opened.

rgs - wanna cherrypick this to maint?

diff --git a/op.c b/op.c
index 9c94cc8..76eb16f 100644
--- a/op.c
+++ b/op.c
@​@​ -5282,14 +5282,11 @​@​ S_looks_like_bool(pTHX_ const OP *o)
&& looks_like_bool(cLOGOPo->op_first->op_sibling));

    case OP\_NULL​:

+ case OP_SCALAR​:
return (
o->op_flags & OPf_KIDS
&& looks_like_bool(cUNOPo->op_first));

- case OP_SCALAR​:
- return looks_like_bool(cUNOPo->op_first);
-
-
case OP_ENTERSUB​:

    case OP\_NOT​:    case OP\_XOR​:

[p5pRT]

@iabyn - Status changed from 'open' to 'resolved'