[xmp] Address compiler warnings

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>

configure.ac

@@ -12,7 +12,7 @@ if test "$libxmp_path" != ""; then
   LIBS="${LIBS} -L${libxmp_path}/lib"
 fi
 
-AC_CHECK_HEADERS(xmp.h getopt.h termios.h alsa/asoundlib.h)
+AC_CHECK_HEADERS(xmp.h getopt.h signal.h termios.h alsa/asoundlib.h)
 
 if test "${ac_cv_header_xmp_h}" = "yes"; then
   AC_CHECK_LIB(xmp,xmp_player_start,,

src/common.h

@@ -22,6 +22,19 @@ struct control {
 	int pause;
 };
 
+
+/* option */
+void get_options(int, char **, struct options *);
+
+/* terminal */
 int set_tty(void);
 int reset_tty(void);
 
+/* info */
+void info_mod(struct xmp_module_info *);
+void info_frame(struct xmp_module_info *, int, int);
+void info_pause(struct xmp_module_info *, int);
+void info_instruments_compact(struct xmp_module_info *);
+
+/* commands */
+void read_command(xmp_context, struct control *);

src/main.c

@@ -1,8 +1,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_SIGNAL_H
 #include <signal.h>
+#endif
 #include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
 #include <xmp.h>
 #include "sound.h"
 #include "common.h"
@@ -13,6 +17,7 @@ extern struct sound_driver sound_null;
 
 struct sound_driver *sound = &sound_alsa;
 
+#ifdef HAVE_SIGNAL_H
 static void cleanup(int sig)
 {
 	signal(SIGTERM, SIG_DFL);
@@ -27,7 +32,7 @@ static void cleanup(int sig)
 	signal(sig, SIG_DFL);
 	kill(getpid (), sig);
 }
-
+#endif
 
 static void shuffle(int argc, char **argv)
 {
@@ -80,11 +85,13 @@ int main(int argc, char **argv)
 		exit(EXIT_FAILURE);
 	}
 
+#ifdef HAVE_SIGNAL_H
 	signal(SIGTERM, cleanup);
 	signal(SIGINT, cleanup);
 	signal(SIGFPE, cleanup);
 	signal(SIGSEGV, cleanup);
 	signal(SIGQUIT, cleanup);
+#endif
 
 	set_tty();
 

src/options.c

@@ -44,11 +44,6 @@ extern int rt;
 
 static void usage(char *s)
 {
-	struct xmp_fmt_info *f, *fmt;
-	struct xmp_drv_info *d, *drv;
-	char **hlp, buf[80];
-	int i;
-
 	printf("Usage: %s [options] [modules]\n", s);
 
 #if 0

src/sound_null.c

@@ -4,6 +4,7 @@
 
 static int init(int sampling_rate, int channels)
 {
+	return 0;
 }
 
 static void play(void *b, int i)