diff options
| -rw-r--r-- | fml/lib/FML/Config.pm | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/fml/lib/FML/Config.pm b/fml/lib/FML/Config.pm index 14cf4114..ac814dc3 100644 --- a/fml/lib/FML/Config.pm +++ b/fml/lib/FML/Config.pm @@ -15,6 +15,7 @@ use Carp; sub new { my ($self) = @_; + my $me = \%_fml_config; return bless $me, $self; } @@ -125,24 +126,40 @@ sub _expand_variables my $max = 0; my $org = ''; - # expand $xxx style variables - no strict 'refs'; - for my $x ( @$order ) { $$x = $config->{ $x };} + # check whether the variable definition is recursive. + # For example, definition "var_a = $var_a/b/c" causes loop. + for my $x ( @$order ) { + if ($config->{ $x } =~ /\$$x/) { + croak("loop1: definition of $x is recursive\n"); + } + } + KEY: for my $x ( @$order ) { - next KEY unless $config->{ $x } =~ /\$/o; - - $max = 0; + next KEY if $config->{ $x } !~ /\$/o; # we need a loop to expand nested variables, for example, # a = $x/y and b = $a/c/0 - EXPAND_LOOP: + # + $max = 0; + EXPANSION_LOOP: while ($max++ < 16) { $org = $config->{ $x }; - $config->{ $x } =~ s/\$([a-z_]+)/${$1}/g; - last EXPAND_LOOP if $org eq $config->{ $x }; + + $config->{ $x } =~ s/\$([a-z_]+)/$config->{$1}/g; + + last EXPANSION_LOOP if $config->{ $x } !~ /\$/o; + last EXPANSION_LOOP if $org eq $config->{ $x }; + + if ($config->{ $x } =~ /\$$x/) { + croak("loop2: definition of $x is recursive\n"); + } } + + if ($max >= 16) { + croak("variable expansion of $x causes infinite loop\n"); + } } } |