From 6a9700a58c52b18e3499ca808099f3452aec8825 Mon Sep 17 00:00:00 2001
From: Oliver Jowett <oliver.jowett@flightaware.com>
Date: Mon, 3 Aug 2020 14:57:31 +0800
Subject: [PATCH] If no explicit library settings are given, try to detect what
 SDRs to support based on what pkg-config knows about.

---
 Makefile | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index b8f03ca..a58dacd 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,22 @@
 PROGNAME=dump1090
 
-RTLSDR ?= yes
-BLADERF ?= yes
-HACKRF ?= yes
+# Try to autodetect available libraries if no explicit setting was used
+
+ifndef RTLSDR
+  ifdef RTLSDR_PREFIX
+    RTLSDR := yes
+  else
+    RTLSDR := $(shell pkg-config --exists librtlsdr && echo "yes" || echo "no")
+  endif
+endif
+
+ifndef BLADERF
+  BLADERF := $(shell pkg-config --exists libbladeRF && echo "yes" || echo "no")
+endif
+
+ifndef HACKRF
+  HACKRF := $(shell pkg-config --exists libhackrf && echo "yes" || echo "no")
+endif
 
 CPPFLAGS += -DMODES_DUMP1090_VERSION=\"$(DUMP1090_VERSION)\" -DMODES_DUMP1090_VARIANT=\"dump1090-fa\"
 
@@ -47,7 +61,14 @@ ifeq ($(HACKRF), yes)
   LIBS_SDR += $(shell pkg-config --libs libhackrf)
 endif
 
-all: dump1090 view1090
+all: showconfig dump1090 view1090
+
+showconfig:
+	@echo "Building with:" >&2
+	@echo "  Version string:  $(DUMP1090_VERSION)" >&2
+	@echo "  RTLSDR support:  $(RTLSDR)" >&2
+	@echo "  BladeRF support: $(BLADERF)" >&2
+	@echo "  HackRF support:  $(HACKRF)" >&2
 
 %.o: %.c *.h
 	$(CC) $(CPPFLAGS) $(CFLAGS) -c $< -o $@