warnings: strip nasmdoc makeup from help strings

When displaying command line help strings, strip nasmdoc markup.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

asm/warnings.pl

diff --git a/asm/warnings.pl b/asm/warnings.pl
index 599a42d..bff566c 100755
--- a/asm/warnings.pl
+++ b/asm/warnings.pl
@@ -11,13 +11,21 @@
 my $err = 0;
 my $nwarn = 0;
 
-sub quote_for_c($) {
+sub quote_for_c(@) {
     my $s = join('', @_);
 
     $s =~ s/([\"\'\\])/\\$1/g;
     return $s;
 }
 
+sub remove_markup(@) {
+    my $s = join('', @_);
+
+    $s =~ s/\\[\w+](\{((?:(?>[^{}]+)|(?1))*)\})?/$2/g;
+    $s =~ s/\\(\W)/$1/g;
+    return $s;
+}
+
 sub add_alias($$) {
     my($a, $this) = @_;
     my @comp = split(/-/, $a);
@@ -162,7 +170,7 @@
 	$#warnings + 2;
     print $out "\tNULL";
     foreach my $warn (@warnings) {
-	my $help = quote_for_c($warn->{help});
+	my $help = quote_for_c(remove_markup($warn->{help}));
 	print $out ",\n\t\"", $help, "\"";
     }
     print $out "\n};\n\n";