Script to detect unused autoconf outputs

Should help speed up mingw builds by a percent or two.

configure.ac

@@ -437,7 +437,6 @@ AC_CHECK_FUNCS([event_get_version \
                 event_get_version_number \
                 event_get_method \
                 event_set_log_callback \
-                evdns_set_outgoing_bind_address \
                 evutil_secure_rng_set_urandom_device_file \
                 evutil_secure_rng_init \
                 event_base_loopexit])
@@ -445,7 +444,7 @@ AC_CHECK_MEMBERS([struct event.min_heap_idx], , ,
 [#include <event.h>
 ])
 
-AC_CHECK_HEADERS(event2/event.h event2/dns.h event2/bufferevent_ssl.h)
+AC_CHECK_HEADERS(event2/event.h event2/dns.h)
 
 LIBS="$save_LIBS"
 LDFLAGS="$save_LDFLAGS"
@@ -1235,7 +1234,6 @@ if [[ $dmalloc -eq 1 ]]; then
   AC_CHECK_HEADERS(dmalloc.h, , AC_MSG_ERROR(dmalloc header file not found. Do you have the development files for dmalloc installed?))
   AC_SEARCH_LIBS(dmalloc_malloc, [dmallocth dmalloc], , AC_MSG_ERROR(Libdmalloc library not found. If you enable it you better have it installed.))
   AC_DEFINE(USE_DMALLOC, 1, [Debug memory allocation library])
-  AC_DEFINE(DMALLOC_FUNC_CHECK, 1, [Enable dmalloc's malloc function check])
   AC_CHECK_FUNCS(dmalloc_strdup dmalloc_strndup)
 fi
 

scripts/README

@@ -6,6 +6,9 @@ Code maintenance scripts
 
 maint/checkLogs.pl -- Verify that Tor log statements are unique.
 
+maint/check_config_macros.pl -- Look for autoconf tests whose results are
+never used.
+
 maint/checkOptionDocs.pl -- Make sure that Tor options are documented in the
 manpage, and that the manpage only documents real Tor options.
 

scripts/maint/check_config_macros.pl

@@ -0,0 +1,20 @@
+#!/usr/bin/perl -w
+
+use strict;
+
+my @macros = ();
+
+open(F, 'orconfig.h.in');
+while(<F>) {
+    if (/^#undef +([A-Za-z0-9_]*)/) {
+	push @macros, $1;
+    }
+}
+close F;
+
+for my $m (@macros) {
+    my $s = `git grep '$m' src`;
+    if ($s eq '') {
+	print "Unused: $m\n";
+    }
+}