[perl #56954] Valid syntax provided by @INC import hook is misparsed

On Tue Jul 15 08:51:19 2008, dheringt wrote:
> This is a bug report for perl from herington_dean@emc.com,
> 
> generated with the help of perlbug 1.35 running under perl v5.8.5.
> 
>  
> 
> The attached program uses an @INC import hook to make two simple
> 
> modules available from text in the program itself.
> 
> `require Mod2` fails with:
> 
>  
> 
>     Missing right curly or square bracket at /loader/0x94ffc20/Mod2.pm
> line 7, at end of line
> 
>     syntax error at /loader/0x94ffc20/Mod2.pm line 7, at EOF
> 
>     Compilation failed in require at INC-sub-bug line 47.
> 
>  
> 
> even though module Mod2 is well-formed Perl code.  Note that
> 
> `require Mod1` succeeds, even though there is only a slight syntactic
> 
> difference between the two modules.
> 

If writing a temporary file isn't a problem then you can use the 
following hook: (which works on perl-5.6.0 - perl-current)

unshift @INC, sub {
  my ($self, $path) = @_;
  if (exists $files{$path}) {
    my ($file) = $path =~ m#([^/]+)$#;
  
    $INC{$path} = "/foo/bar/baz";
 
    my $t = "/tmp/perl_${file}_$$";
    open my $fh, ">", $t or die "Can't open file: $!";
    print $fh $files{$path};
    close $fh;

    open my $fh2, "<", $t or die "Can't open file: $!";
    return ($fh2, sub {
      if (not length $_) {
        close $fh2;
        unlink $t;
      }
      return length $_;
    });
  }
  return;
};



The 'normal' way would have been:

#!/usr/bin/perl -wl

use strict;

my %files;
$files{"Mod1.pm"} = <<'END';

package Mod1;

sub subr {
  my ($path) = @_;
  open FH1, "<", $path   
    or die;
}

1;

END

$files{"Mod2.pm"} = <<'END';

package Mod2;
sub subr {
  my ($path) = @_;
  open FH2, "<", $path
  or die;
}

1;

END

unshift @INC, sub {
  my ($self, $path) = @_;
  if (exists $files{$path}) {
    $INC{$path} = "/foo/bar/baz";

    my @lines = split /\n/, $files{$path};
    my $i = 0;
    return (sub {
      if ($i >= @lines) {
        return 0;
      }
      $_ = $lines[$i++];
      return 1;
    });
  }
  return;
};

require Mod1;
require Mod2;
__END__
perl-5.6.0 rt-56954.pl 
Number found where operator expected at /loader/0x811024c/Mod1.pm line 
10, near "1"
        (Missing semicolon on previous line?)
syntax error at /loader/0x811024c/Mod1.pm line 10, near "1"
Missing right curly or square bracket at /loader/0x811024c/Mod1.pm line 
10, at end of line
Compilation failed in require at rt-56954.pl line 51.


perl-5.8.8 rt-56954.pl 
Number found where operator expected at /loader/0x812c98c/Mod1.pm line 
10, near "1"
        (Missing semicolon on previous line?)
syntax error at /loader/0x812c98c/Mod1.pm line 10, near "1"
Missing right curly or square bracket at /loader/0x812c98c/Mod1.pm line 
10, at end of line
Compilation failed in require at rt-56954.pl line 51.


perl-5.8.9-tobe rt-56954.pl
(no output - good)

perl-5.10.0 rt-56954.pl 
(no output - good)

perl-blead rt-56954.pl
(no output - good)



Kind regards,

Bram

• [perl #56954] Valid syntax provided by @INC import hook is misparsed by Bram via RT