regcomp.pl - fixup intflags debug data to handle gaps properly

We were not handling gaps in the sequence properly, and effectively
showing the wrong flag names or missing the last flag. Now we die if there
are any collisions or if any of the PREGf defines set more than one bit.
This also adds some crude tests to validate that intflags serialization is
working properly.

Note, extflags handles more complex scenarios and seems to handle this
gracefully already, hence the reason I haven't touched it as well.

This also tweaks a comment in lexical_debug.t which part of this was
cribbed from.

1 files changed, 19 insertions, 4 deletions

diff --git a/regen/regcomp.pl b/regen/regcomp.pl
index 4999cfa034..94a53dbbb6 100644
--- a/regen/regcomp.pl
+++ b/regen/regcomp.pl
@@ -726,8 +726,10 @@ EOP
     my %reverse;
     my $REG_INTFLAGS_NAME_SIZE= 0;
     my $hp= HeaderParser->new();
+    my $last_val = 0;
     foreach my $file ("regcomp.h") {
         $hp->read_file($file);
+        my @bit_tuples;
         foreach my $line_info (@{$hp->lines}) {
             next unless $line_info->{type}     eq "content"
                     and $line_info->{sub_type} eq "#define";
@@ -745,13 +747,26 @@ EOP
                 my $hex= $3;
                 my $comment= $4;
                 my $val= hex($hex);
+                my $bin= sprintf "%b", $val;
+                if ($bin=~/1.*?1/) { die "Not expecting multiple bits in PREGf" }
+                my $bit= length($bin) - 1 ;
                 $comment= $comment ? " - $comment" : "";
-
-                printf $out qq(\t%-30s/* 0x%08x - %s%s */\n), qq("$abbr",),
-                    $val, $define, $comment;
-                $REG_INTFLAGS_NAME_SIZE++;
+                if ($bit_tuples[$bit]) {
+                    die "Duplicate PREGf bit '$bit': $define $val ($hex)";
+                }
+                $bit_tuples[$bit]= [ $bit, $val, $abbr, $define, $comment ];
+            }
+        }
+        foreach my $i (0..$#bit_tuples) {
+            my $bit_tuple= $bit_tuples[$i];
+            if (!$bit_tuple) {
+                $bit_tuple= [ $i, 1<<$i, "", "", "*UNUSED*" ];
             }
+            my ($bit, $val, $abbr, $define, $comment)= @$bit_tuple;
+            printf $out qq(\t%-30s/* (1<<%2d) - 0x%08x - %s%s */\n),
+                qq("$abbr",), $bit, $val, $define, $comment;
         }
+        $REG_INTFLAGS_NAME_SIZE=0+@bit_tuples;
     }
 
     print $out <<EOP;