source cleanup: unify look, style and indent levels

By the use of a the new lib/checksrc.pl script that checks that our
basic source style rules are followed.

lib/checksrc.pl

@@ -0,0 +1,118 @@
+#!/usr/bin/perl
+
+my $file=$ARGV[0];
+
+my $max_column = 79;
+my $indent = 2;
+
+sub checkwarn {
+    my ($num, $col, $file, $line, $msg, $error) = @_;
+
+    my $w=$error?"error":"warning";
+
+    $col++;
+    print "$file:$num:$col: $w: $msg\n";
+    print " $line\n";
+
+    if($col < 80) {
+        my $pref = (' ' x $col);
+        print "${pref}^\n";
+    }
+}
+
+if(!$file) {
+    print "checksrc.pl <single C or H file>\n";
+    exit;
+}
+
+
+my $line = 1;
+open(R, "<$file") || die;
+
+my $copyright=0;
+
+while(<R>) {
+    chomp;
+    my $l = $_;
+    my $column = 0;
+
+    # check for a copyright statement
+    if(!$copyright && ($l =~ /copyright .* \d\d\d\d/i)) {
+        $copyright=1;
+    }
+
+    # detect long lines
+    if(length($l) > $max_column) {
+        checkwarn($line, length($l), $file, $l, "Longer than $max_column columns");
+    }
+    # detect TAB characters
+    if($l =~ /^(.*)\t/) {
+        checkwarn($line, length($1), $file, $l, "Contains TAB character", 1);
+    }
+    # detect trailing white space
+    if($l =~ /^(\S+)[ \t]+\z/) {
+        checkwarn($line, length($1), $file, $l, "Trailing whitespace");
+    }
+
+    # detect return statements with parenthesis
+    # doesn't really work unless we filter off typecasts
+    #if($l =~ /(.*)return \(/) {
+    #    checkwarn($line, length($1)+6, $file, $l, "return with paretheses");
+    #}
+
+    # check spaces after for/if/while
+    if($l =~ /^(.*)(for|if|while) \(/) {
+        if($1 =~ / *\#/) {
+            # this is a #if, treat it differently
+        }
+        else {
+            checkwarn($line, length($1)+length($2), $file, $l,
+                      "$2 with space");
+        }
+    }
+    # check for "} else"
+    if($l =~ /^(.*)\} else/) {
+        checkwarn($line, length($1), $file, $l, "else after closing brace on same line");
+    }
+    # check for open brace first on line but not first column
+    # only alert if previous line ended with a close paren and wasn't a cpp
+    # line
+    if((($prevl =~ /\)\z/) && ($prevl !~ /^ *#/)) && ($l =~ /^( +)\{/)) {
+        checkwarn($line, length($1), $file, $l, "badly placed open brace");
+    }
+
+    # if the previous line starts with if/while/for AND ends with an open
+    # brace, check that this line is indented $indent more steps, if not
+    # a cpp line
+    if($prevl =~ /^( *)(if|while|for)\(.*\{\z/) {
+        my $first = length($1);
+
+        # this line has some character besides spaces
+        if(($l !~ /^ *#/) && ($l =~ /^( *)[^ ]/)) {
+            my $second = length($1);
+            my $expect = $first+$indent;
+            if($expect != $second) {
+                my $diff = $second - $first;
+                checkwarn($line, length($1), $file, $l,
+                          "not indented $indent steps, uses $diff)");
+
+            }
+        }
+    }
+
+    # check for // letters, but skip them if a double quote or asterisk was
+    # on the same line to avoid strings and comments. Not reliable.
+    #if($l =~ /^([^\"*]*)\/\//) {
+    #    checkwarn($line, length($1), $file, $l, "non-C89 compliant comment",
+    #              1);
+    #}
+
+    $line++;
+    $prevl = $l;
+}
+
+if(!$copyright) {
+    checkwarn(1, 0, $file, "", "Missing copyright statement", 1);
+}
+
+close(R);