check-help-strings.pl: work better when running in a subdir

The script used to get confused if you ran it in a subdir of the OMPI
tree (e.g., it would report help files not found if source code
referred to a help file that was not under the subdir in which it was
run).

Now the script searches the whole tree for help files, but only
analyzes the source from the subdir in which it was started.  Meaning:
it should always find all help files, and won't get confused like it
did before.

This commit was SVN r32548.

contrib/check-help-strings.pl

@@ -117,7 +117,11 @@ sub match_files {
 
 # Find all source and help files
 print "Searching for source and help files...\n";
-print "Starting in: $start\n";
+my $startrel = $start;
+if ($top ne $start) {
+    $startrel =~ s/^$top//;
+    $startrel =~ s/^\///;
+}
 find(\&match_files, ".");
 
 ###########################################################################
@@ -126,7 +130,7 @@ find(\&match_files, ".");
 my $help_topics;
 my $help_file_refs;
 
-print "Indexing help files...\n";
+print "Indexing help files (from entire source tree)...\n";
 
 foreach my $info (@help_files) {
     verbose("Indexing help: $info->{full}\n");
@@ -175,7 +179,11 @@ foreach my $info (@help_files) {
 
 # Search source files for calls to opal_show_help and (o)rte_show_help
 
-print "Searching source files...\n";
+if ($start eq $top) {
+    print "Searching source files (from entire source tree)...\n";
+} else {
+    print "Searching source files (under $startrel)...\n";
+}
 
 # Helper: for a given filename/topic, see if it exists
 sub check_file_topic {
@@ -235,6 +243,10 @@ sub check_name {
 foreach my $info (@source_files) {
     verbose("Searching source: $info->{full}\n");
 
+    # If this source file is not in the target area, then skip it
+    next
+        if ($info->{relative} != /^$startrel/);
+
     my $src;
     open(FH, $info->{full}) || die "Can't open $info->{full}";
     while (<FH>) {