Perl's chop / chomp considered bad, use a regexp instead

Once upon a time, there was chop, which somply chopped off the last
character of $_ or a given variable, and it was used to take off the
EOL character (\n) of strings.

... but then, you had to check for the presence of such character.

So came chomp, the better chop which checks for \n before chopping it
off.  And this worked well, as long as Perl made internally sure that
all EOLs were converted to \n.

These days, though, there seems to be a mixture of perls, so lines
from files in the "wrong" environment might have \r\n as EOL, or just
\r (Mac OS, unless I'm misinformed).

So it's time we went for the more generic variant and use s|\R$||, the
better chomp which recognises all kinds of known EOLs and chops them
off.

A few chops were left alone, as they are use as surgical tools to
remove one last slash or one last comma.

NOTE: \R came with perl 5.10.0.  It means that from now on, our
scripts will fail with any older version.

Reviewed-by: Rich Salz <rsalz@openssl.org>

10 files changed, 23 insertions, 25 deletions

diff --git a/util/check-buildinfo.pl b/util/check-buildinfo.pl
index 176b956..f7d3baa 100644
--- a/util/check-buildinfo.pl
+++ b/util/check-buildinfo.pl
@@ -7,7 +7,7 @@ my $reldir = "";
 my $searchterm = "";
 my $goal = "";
 while (<$minfo>) {
-    chomp;
+    s|\R$||;
 
     if (/^RELATIVE_DIRECTORY=(.*)$/) {
         $reldir=$1;
diff --git a/util/extract-names.pl b/util/extract-names.pl
index 35bd6ed..0f69335 100644
--- a/util/extract-names.pl
+++ b/util/extract-names.pl
@@ -2,7 +2,7 @@
 
 $/ = "";			# Eat a paragraph at once.
 while(<STDIN>) {
-    chop;
+    s|\R$||;
     s/\n/ /gm;
     if (/^=head1 /) {
 	$name = 0;
diff --git a/util/files.pl b/util/files.pl
index d5c78ba..d984196 100755
--- a/util/files.pl
+++ b/util/files.pl
@@ -13,7 +13,7 @@ while ($ARGV[0] =~ /^([^\s=]+)\s*=\s*(.*)$/)
 $s="";
 while (<>)
 	{
-	chop;
+	s|\R$||;
 	s/#.*//;
 	if (/^([^\s=]+)\s*=\s*(.*)$/)
 		{
@@ -23,10 +23,10 @@ while (<>)
 			{
 			if ($b =~ /\\$/)
 				{
-				chop($b);
+				$b=$`; # Keep what is before the backslash
 				$o.=$b." ";
 				$b=<>;
-				chop($b);
+				$b =~ s|\R$||; # Better chomp
 				}
 			else
 				{
@@ -43,7 +43,7 @@ while (<>)
 		}
 	}
 
-$pwd=`pwd`; chop($pwd);
+$pwd=`pwd`; $pwd =~ s|\R$||;
 
 if ($sym{'TOP'} eq ".")
 	{
@@ -55,7 +55,7 @@ else	{
 	@_=split(/\//,$pwd);
 	$z=$#_-$n+1;
 	foreach $i ($z .. $#_) { $dir.=$_[$i]."/"; }
-	chop($dir);
+	chop($dir);             # Remove the last slash
 	}
 
 print "RELATIVE_DIRECTORY=$dir\n";
diff --git a/util/fipslink.pl b/util/fipslink.pl
index 4a88fc6..7b16e04 100644
--- a/util/fipslink.pl
+++ b/util/fipslink.pl
@@ -59,7 +59,7 @@ open my $sha1_res, '<', $fips_target.".sha1" or die "Get hash failure";
 $fips_hash=<$sha1_res>;
 close $sha1_res;
 unlink $fips_target.".sha1";
-chomp $fips_hash;
+$fips_hash =~ s|\R$||;          # Better chomp
 die "Get hash failure" if $? != 0;
 
 
@@ -97,8 +97,8 @@ sub check_hash
 	$hashfile = <IN>;
 	close IN;
 	$hashval = `$sha1_exe ${fips_libdir}/$filename`;
-	chomp $hashfile;
-	chomp $hashval;
+	$hashfile =~ s|\R$||;    # Better chomp
+	$hashval =~ s|\R$||;     # Better chomp
 	$hashfile =~ s/^.*=\s+//;
 	$hashval =~ s/^.*=\s+//;
 	die "Invalid hash syntax in file" if (length($hashfile) != 40);
diff --git a/util/mk1mf.pl b/util/mk1mf.pl
index 4144130..3a9f0d7 100755
--- a/util/mk1mf.pl
+++ b/util/mk1mf.pl
@@ -553,7 +553,7 @@ if ($fips)
 			{
 			open (IN, "util/fipslib_path.txt") || fipslib_error();
 			$fipslibdir = <IN>;
-			chomp $fipslibdir;
+			$fipslibdir =~ s|\R$||;
 			close IN;
 			}
 		fips_check_files($fipslibdir,
@@ -1159,7 +1159,7 @@ sub do_defs
 		elsif ($var eq "SSLOBJ")
 			{ $ret.="\$(OBJ_D)\\\$(SSL).res "; }
 		}
-	chomp($ret);
+	chomp($ret);            # Does this actually do something? /RL
 	$ret.="\n\n";
 	return($ret);
 	}
diff --git a/util/mkdef.pl b/util/mkdef.pl
index aa85ec8..b5ebc18 100755
--- a/util/mkdef.pl
+++ b/util/mkdef.pl
@@ -459,7 +459,7 @@ sub do_defs
 			if($parens > 0) {
 				#Inside a DEPRECATEDIN
 				$stored_multiline .= $_;
-				chomp $stored_multiline;
+				$stored_multiline =~ s|\R$||; # Better chomp
 				print STDERR "DEBUG: Continuing multiline DEPRECATEDIN: $stored_multiline\n" if $debug;
 				$parens = count_parens($stored_multiline);
 				if ($parens == 0) {
@@ -480,9 +480,7 @@ sub do_defs
 			}
 
 			if (/\\$/) {
-				chomp; # remove eol
-				chop; # remove ending backslash
-				$line = $_;
+				$line = $`; # keep what was before the backslash
 				next;
 			}
 
@@ -499,7 +497,7 @@ sub do_defs
 				$cpp++ if /^#\s*if/;
 				$cpp-- if /^#\s*endif/;
 				next;
-	    		}
+			}
 			$cpp = 1 if /^#.*ifdef.*cplusplus/;
 
 			s/{[^{}]*}//gs;                      # ignore {} blocks
@@ -867,7 +865,7 @@ sub do_defs
 							\@current_algorithms);
 					} else {
 						$stored_multiline = $_;
-						chomp $stored_multiline;
+						$stored_multiline =~ s|\R$||;
 						print STDERR "DEBUG: Found multiline DEPRECATEDIN starting with: $stored_multiline\n" if $debug;
 						next;
 					}
@@ -1365,7 +1363,7 @@ sub load_numbers
 
 	open(IN,"<$name") || die "unable to open $name:$!\n";
 	while (<IN>) {
-		chop;
+		s|\R$||;        # Better chomp
 		s/#.*$//;
 		next if /^\s*$/;
 		@a=split;
diff --git a/util/mkerr.pl b/util/mkerr.pl
index 13c9974..939a87c 100644
--- a/util/mkerr.pl
+++ b/util/mkerr.pl
@@ -556,7 +556,7 @@ EOF
 	if (open(IN,"<$cfile")) {
 		my $line = "";
 		while (<IN>) {
-			chomp;
+			s|\R$||; # Better chomp
 			$_ = $line . $_;
 			$line = "";
 			if (/{ERR_(FUNC|REASON)\(/) {
diff --git a/util/mkfiles.pl b/util/mkfiles.pl
index d668316..4fbe29a 100755
--- a/util/mkfiles.pl
+++ b/util/mkfiles.pl
@@ -95,7 +95,7 @@ my $s="";
 
 while (<IN>)
 	{
-	chop;
+	s|\R$||;
 	s/#.*//;
 	if (/^([^\s=]+)\s*=\s*(.*)$/)
 		{
@@ -105,10 +105,10 @@ while (<IN>)
 			{
 			if ($b =~ /\\$/)
 				{
-				chop($b);
+				$b=$`;
 				$o.=$b." ";
 				$b=<IN>;
-				chop($b);
+				$b =~ s|\R$||;
 				}
 			else
 				{
diff --git a/util/selftest.pl b/util/selftest.pl
index 59842ef..06d494a 100644
--- a/util/selftest.pl
+++ b/util/selftest.pl
@@ -54,7 +54,7 @@ $cversion=`$cc -V |head -1` if $cversion =~ "Error";
 $cversion=`$cc --version` if $cversion eq "";
 $cversion =~ s/Reading specs.*\n//;
 $cversion =~ s/usage.*\n//;
-chomp $cversion;
+$cversion =~ s|\R$||;
 
 if (open(IN,"<CHANGES")) {
     while(<IN>) {
diff --git a/util/sp-diff.pl b/util/sp-diff.pl
index 9d6c603..57e635b 100755
--- a/util/sp-diff.pl
+++ b/util/sp-diff.pl
@@ -54,7 +54,7 @@ sub loadfile
 		$header=0 if /^[dr]sa/;
 		if (/^type/) { $header=0; next; }
 		next if $header;
-		chop;
+		s|\R$||;
 		@a=split;
 		if ($a[0] =~ /^[dr]sa$/)
 			{