Validate that FIUs' LFSR masks only use bits within the LFSR's width

bin/FIJI.pm

@@ -835,6 +835,17 @@ BEGIN {
                 my $mask_width = defined($design_ref) && defined($design_ref->{'LFSR_WIDTH'}) ? $design_ref->{'LFSR_WIDTH'} : 1;
                 return 1 << ($i % $mask_width);
             },
+            values     => sub {
+                my ($val, $old, $map_ref, $consts_ref, $lfsr_width) = @_;
+                return 0 if $val <= 0;
+                # If the width is bogus, we cannot do much but ignore them here
+                # FIXME: we should not ever get hex numbers in lfsr_width, however we do
+                # because they don't get stored as numbers in the settings
+                return 1 if (!defined($lfsr_width) || $lfsr_width !~ /^[1-9][0-9]*$/);
+                my $mask_width = log($val+1)/log(2);
+                return $lfsr_width >= $mask_width;
+            },
+            depends_on => 'LFSR_WIDTH',
             type       => 'hexadecimal',
             help       => "Selects the bits of the LFSR that are ANDed together to determine the value of a floating net.",
             phases_opt => [qw(setup)],

bin/Tk/FIJISettingsViewer.pm

@@ -186,6 +186,12 @@ sub update {
     my $self   = shift;
     my $logger = get_logger("");
 
+    # Before anything else the list of widgets depending on LFSR_WIDTH needs to be cleaned up.
+    # All references to existing FIU widgets will become invalid because the widgets are replaced.
+    # Thus the code below filters them out by their key field and leaves only constants from DESIGNMAP (e.g., LFSR_POLY).
+    my @all_but_lfsr_masks = grep { $_->{'key'} !~ "FIU([0-9]+)_LFSR_MASK" } @{$self->{'depends'}->{'LFSR_WIDTH'}};
+    $self->{'depends'}->{'LFSR_WIDTH'} = \@all_but_lfsr_masks;
+
     #################
     # design panels #
     #################
@@ -1088,6 +1094,11 @@ sub _add_fiu_widgets {
     $mask_entry->{'key'}          = "FIU${i}_LFSR_MASK";
     Tk::FIJIUtils::entry_rebind($mask_entry);
 
+    # Register dependency for LFSR_MASK(s) (of FIUMAP) on LFSR_WIDTH (of DESIGN_MAP)
+    if (defined(FIUMAP->{'FIU_LFSR_MASK'}->{'depends_on'})) { # Should be always true
+        push(@{$self->{'depends'}->{FIUMAP->{'FIU_LFSR_MASK'}->{'depends_on'}}}, $mask_entry);
+    }
+
     $self->{'balloon'}->attach(
         $mask_entry,
         -balloonposition => 'mouse',