From 888c939a755840d37b6695c525c3c0db6b114a4d Mon Sep 17 00:00:00 2001
From: Oliver Jowett <oliver@mutability.co.uk>
Date: Thu, 2 Feb 2017 13:47:19 +0000
Subject: [PATCH] Include enabled compile-time build options in the help
 header.

---
 dump1090.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/dump1090.c b/dump1090.c
index d3d6076..82eda50 100644
--- a/dump1090.c
+++ b/dump1090.c
@@ -260,11 +260,28 @@ void snipMode(int level) {
 // ================================ Main ====================================
 //
 void showHelp(void) {
-    printf(
-           "-----------------------------------------------------------------------------\n"
-           "| dump1090 ModeS Receiver     %45s |\n"
-           "-----------------------------------------------------------------------------\n",
-           MODES_DUMP1090_VARIANT " " MODES_DUMP1090_VERSION);
+
+    printf("-----------------------------------------------------------------------------\n");
+    printf("| dump1090 ModeS Receiver     %45s |\n", MODES_DUMP1090_VARIANT " " MODES_DUMP1090_VERSION);
+    printf("| build options: %-58s |\n",
+           ""
+#ifdef ENABLE_RTLSDR
+           "ENABLE_RTLSDR "
+#endif
+#ifdef ENABLE_BLADERF
+           "ENABLE_BLADERF "
+#endif
+#ifdef SC16Q11_TABLE_BITS
+    // This is a little silly, but that's how the preprocessor works..
+#define _stringize(x) #x
+#define stringize(x) _stringize(x)
+           "SC16Q11_TABLE_BITS=" stringize(SC16Q11_TABLE_BITS)
+#undef stringize
+#undef _stringize
+#endif
+           );
+    printf("-----------------------------------------------------------------------------\n");
+    printf("\n");
 
     sdrShowHelp();