From @cpansprout

$ perl -le' sub foo($) { print "foo" }; foo $_, exit'
foo
$ perl -le' sub foo(\$) { print "foo" }; foo $_, exit'
Too many arguments for main​::foo at -e line 1, at EOF
Execution of -e aborted due to compilation errors.

So it looks as though the parser does not consider it unary, but op.c
does.

Flags​:
  category=core
  severity=low

Site configuration information for perl 5.13.1​:

Configured by sprout at Tue Jun 15 06​:25​:06 PDT 2010.

Summary of my perl5 (revision 5 version 13 subversion 1 patch
v5.13.1-196-gee84a79) configuration​:
  Snapshot of​: ee84a79
  Platform​:
  osname=darwin, osvers=10.0.0, archname=darwin-2level
  uname='darwin pint.local 10.0.0 darwin kernel version 10.0.0​: fri
jul 31 22​:47​:34 pdt 2009; root​:xnu-1456.1.25~1release_i386 i386 '
  config_args='-de -Dusedevel -DDEBUGGING'
  hint=recommended, useposix=true, d_sigaction=define
  useithreads=undef, usemultiplicity=undef
  useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
  use64bitint=undef, use64bitall=undef, uselongdouble=undef
  usemymalloc=n, bincompat5005=undef
  Compiler​:
  cc='cc', ccflags ='-fno-common -DPERL_DARWIN -no-cpp-precomp -
DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/
include',
  optimize='-O3 -g',
  cppflags='-no-cpp-precomp -fno-common -DPERL_DARWIN -no-cpp-
precomp -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/
usr/local/include'
  ccversion='', gccversion='4.2.1 (Apple Inc. build 5646)',
gccosandvers=''
  intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
  ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t',
lseeksize=8
  alignbytes=8, prototype=define
  Linker and Libraries​:
  ld='env MACOSX_DEPLOYMENT_TARGET=10.3 cc', ldflags =' -fstack-
protector -L/usr/local/lib'
  libpth=/usr/local/lib /usr/lib
  libs=-ldbm -ldl -lm -lutil -lc
  perllibs=-ldl -lm -lutil -lc
  libc=/usr/lib/libc.dylib, so=dylib, useshrplib=false,
libperl=libperl.a
  gnulibc_version=''
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=bundle, d_dlsymun=undef, ccdlflags=' '
  cccdlflags=' ', lddlflags=' -bundle -undefined dynamic_lookup -L/
usr/local/lib -fstack-protector'

Locally applied patches​:

@​INC for perl 5.13.1​:
  /usr/local/lib/perl5/site_perl/5.13.1/darwin-2level
  /usr/local/lib/perl5/site_perl/5.13.1
  /usr/local/lib/perl5/5.13.1/darwin-2level
  /usr/local/lib/perl5/5.13.1
  /usr/local/lib/perl5/site_perl
  .

Environment for perl 5.13.1​:
  DYLD_LIBRARY_PATH (unset)
  HOME=/Users/sprout
  LANG=en_US.UTF-8
  LANGUAGE (unset)
  LD_LIBRARY_PATH (unset)
  LOGDIR (unset)
  PATH=/usr/bin​:/bin​:/usr/sbin​:/sbin​:/usr/local/bin​:/usr/X11/bin​:/
usr/local/bin
  PERL_BADLANG (unset)
  SHELL=/bin/bash

From @cpansprout

On Jun 20, 2010, at 2​:32 PM, Father Chrysostomos wrote​:

$ perl -le' sub foo($) { print "foo" }; foo $_, exit'
foo
$ perl -le' sub foo(\$) { print "foo" }; foo $_, exit'
Too many arguments for main​::foo at -e line 1, at EOF
Execution of -e aborted due to compilation errors.

So it looks as though the parser does not consider it unary, but op.c does.

This problem is worse than I thought. It applies to these prototypes as well​:

*
\sigil
\[...]
;$
;*
;\sigil
;\[...]

This means that the following functions, among others, cannot be overridden by subs that parse the same way​:

fileno (*)
chdir (;$)
close (;*)
dbmclose (\%)
tied (\[$@​%*])
pop (;\@​)

The attached patch fixes these. I hope no-one minds the space-out ‘if’ condition. I just find it *much* easier to read that way.

From @cpansprout

--- blead/toke.c	2010-07-17 18:51:14.000000000 -0700
+++ blead-ref-proto/toke.c	2010-07-19 22:03:26.000000000 -0700
@@ -6493,10 +6493,27 @@ Perl_yylex(pTHX)
 			const char *proto = SvPV_const(MUTABLE_SV(cv), protolen);
 			if (!protolen)
 			    TERM(FUNC0SUB);
-			if ((*proto == '$' || *proto == '_') && proto[1] == '\0')
-			    OPERATOR(UNIOPSUB);
 			while (*proto == ';')
 			    proto++;
+			if (
+			    (
+			        (
+			            *proto == '$' || *proto == '_'
+			         || *proto == '*'
+			        )
+			     && proto[1] == '\0'
+			    )
+			 || (
+			     *proto == '\\' && proto[1] && proto[2] == '\0'
+			    )
+			)
+			    OPERATOR(UNIOPSUB);
+			if (*proto == '\\' && proto[1] == '[') {
+			    const char *p = proto + 2;
+			    while(*p && *p != ']')
+				++p;
+			    if(*p == ']' && !p[1]) OPERATOR(UNIOPSUB);
+			}
 			if (*proto == '&' && *s == '{') {
 			    if (PL_curstash)
 				sv_setpvs(PL_subname, "__ANON__");
--- blead/t/comp/proto.t	2009-11-19 08:51:40.000000000 -0800
+++ blead-ref-proto/t/comp/proto.t	2010-07-19 21:32:28.000000000 -0700
@@ -18,7 +18,7 @@ BEGIN {
 # strict
 use strict;
 
-print "1..153\n";
+print "1..160\n";
 
 my $i = 1;
 
@@ -651,3 +651,28 @@ print "ok ", $i++, "\n";
 eval 'sub bug (\[%@]) {  } my $array = [0 .. 1]; bug %$array;';
 print "not " unless $@ =~ /Not a HASH reference/;
 print "ok ", $i++, "\n";
+
+# [perl #75904]
+# Test that the following prototypes make subs parse as unary functions:
+#  * \sigil \[...] ;$ ;* ;\sigil ;\[...]
+print "not "
+ unless eval 'sub uniproto1 (*) {} uniproto1 $_, 1' or warn $@;
+print "ok ", $i++, "\n";
+print "not "
+ unless eval 'sub uniproto2 (\$) {} uniproto2 $_, 1' or warn $@;
+print "ok ", $i++, "\n";
+print "not "
+ unless eval 'sub uniproto3 (\[$%]) {} uniproto3 %_, 1' or warn $@;
+print "ok ", $i++, "\n";
+print "not "
+ unless eval 'sub uniproto4 (;$) {} uniproto4 $_, 1' or warn $@;
+print "ok ", $i++, "\n";
+print "not "
+ unless eval 'sub uniproto5 (;*) {} uniproto5 $_, 1' or warn $@;
+print "ok ", $i++, "\n";
+print "not "
+ unless eval 'sub uniproto6 (;\@) {} uniproto6 @_, 1' or warn $@;
+print "ok ", $i++, "\n";
+print "not "
+ unless eval 'sub uniproto7 (;\[$%@]) {} uniproto7 @_, 1' or warn $@;
+print "ok ", $i++, "\n";

From @rgarcia

On 25 July 2010 21​:43, Father Chrysostomos <sprout@​cpan.org> wrote​:

On Jun 20, 2010, at 2​:32 PM, Father Chrysostomos wrote​:

$ perl -le' sub foo($) { print "foo" }; foo $_, exit'
foo
$ perl -le' sub foo(\$) { print "foo" }; foo $_, exit'
Too many arguments for main​::foo at -e line 1, at EOF
Execution of -e aborted due to compilation errors.

So it looks as though the parser does not consider it unary, but op.c does.

This problem is worse than I thought. It applies to these prototypes as well​:

*
\sigil
\[...]
;$
;*
;\sigil
;\[...]

This means that the following functions, among others, cannot be overridden by subs that parse the same way​:

fileno (*)
chdir (;$)
close (;*)
dbmclose (\%)
tied (\[$@​%*])
pop (;\@​)

The attached patch fixes these. I hope no-one minds the space-out ‘if’ condition. I just find it *much* easier to read that way.

The patch looks good and the result is more consistent parsing. Also,
I believe that it's not really breaking backwards compatibility, since
it turns previous parse errors into valid constructs (right?)

Opinions ? Should I apply ?

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

From @rafl

Rafael Garcia-Suarez <rgs@​consttype.org> writes​:

On 25 July 2010 21​:43, Father Chrysostomos <sprout@​cpan.org> wrote​:
The patch looks good and the result is more consistent parsing. Also,
I believe that it's not really breaking backwards compatibility, since
it turns previous parse errors into valid constructs (right?)

Opinions ? Should I apply ?

It also looks good to me, passes all tests, and does fix an actual
problem. I'm all for this being applied.

From @rgs

Thanks, applied to bleadperl as 649d02d

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