Avoid librtlsdr dependency for utilities that don't use it.

Tne only place that really needs the rtlsdr headers/libs is dump1090.c
itself. There is a dependency on rtlsdr_dev_t in the shared Modes
struct in dump1090.h, but this is a pointer type so we can just
use a dummy struct definition there to avoid the header dependency.

This lets us build faup1090 (for the piaware package) without
needing a useless librtlsdr-dev build-time dependency.

dump1090.c

@@ -29,6 +29,7 @@
 //
 #include "coaa.h"
 #include "dump1090.h"
+#include "rtl-sdr.h"
 //
 // ============================= Utility functions ==========================
 //

dump1090.h

@@ -57,11 +57,9 @@
     #include <ctype.h>
     #include <sys/stat.h>
     #include <sys/ioctl.h>
-    #include "rtl-sdr.h"
     #include "anet.h"
 #else
     #include "winstubs.h" //Put everything Windows specific in here
-    #include "rtl-sdr.h"
     #include "anet.h"
 #endif
 
@@ -187,6 +185,10 @@
 
 //======================== structure declarations =========================
 
+// forward declaration of RTL-SDR device struct to avoid a dependency
+// on RTL-SDR for those utils that don't actually use it
+typedef struct rtlsdr_dev rtlsdr_dev_t;
+
 // Structure used to describe a networking client
 struct client {
     struct client*  next;                // Pointer to next client

makeppup1090

@@ -10,8 +10,8 @@ SHAREDIR=$(PREFIX)/share/$(PROGNAME)
 EXTRACFLAGS=-DHTMLPATH=\"$(SHAREDIR)\"
 endif
 
-CFLAGS=-O2 -g -Wall -W `pkg-config --cflags librtlsdr`
-LIBS=`pkg-config --libs librtlsdr` -lpthread -lm
+CFLAGS=-O2 -g -Wall -W
+LIBS=-lpthread -lm
 CC=gcc
 
 

makeview1090

@@ -10,8 +10,8 @@ SHAREDIR=$(PREFIX)/share/$(PROGNAME)
 EXTRACFLAGS=-DHTMLPATH=\"$(SHAREDIR)\"
 endif
 
-CFLAGS=-O2 -g -Wall -W `pkg-config --cflags librtlsdr`
-LIBS=`pkg-config --libs librtlsdr` -lpthread -lm
+CFLAGS=-O2 -g -Wall -W
+LIBS=-lpthread -lm
 CC=gcc
 
 

ppup1090.h

@@ -52,7 +52,6 @@
     #include <fcntl.h>
     #include <ctype.h>
     #include <sys/stat.h>
-    #include "rtl-sdr.h"
     #include "anet.h"
     #include <netdb.h>
 #else

view1090.h

@@ -51,7 +51,6 @@
     #include <sys/stat.h>
     #include <sys/types.h>
     #include <sys/socket.h>
-    #include "rtl-sdr.h"
     #include "anet.h"
 #else
     #include "winstubs.h" //Put everything Windows specific in here