Patch to fix ftbfs with GCC-5
This is mostly removing unused variables and functions.
colint@debian.org

--- a/fsk/modem.c
+++ b/fsk/modem.c
@@ -148,7 +148,7 @@
 {
         struct modstate *s = (struct modstate *)state;
 	int i, j;
-	float f1, f2, time, alphatime;
+	float f1, f2, time;
 	float c[NUMFILTER * FILTERLEN];
 
 	s->phaseinc = (s->bps << 16) / samplerate;
@@ -356,6 +356,7 @@
 	return fir(s->filter[WHICHFILTER(ph)], samples + WHICHSAMPLE(ph), s->firlen);
 }
 
+#if 0
 static int16_t equalizer(struct demodstate *s, int16_t s1, int16_t s2)
 {
 	int16_t target;
@@ -376,6 +377,7 @@
  printf("%5d %5d %5d %5d %5d\n", s->eqf[0], s->eqf[1], s->eqf[2], s->eqf[3], s->eqf[4]);
 	return sum;
 }
+#endif
 
 static const struct modemparams demodparams[] = {
         { "bps", "Bits/s", "Bits per second", "9600", MODEMPAR_NUMERIC, { n: { 4800, 38400, 100, 1200 } } },
@@ -416,11 +418,15 @@
 static void demodrx(struct demodstate *s, unsigned nsamples)
 {
 	int16_t *samples;
- 	int16_t curs, nexts, mids, xs, eq;
-	int32_t gardner;
-	unsigned int d, descx;
+ 	int16_t curs, nexts, mids;
+	unsigned int descx;
 	unsigned char ch[3];
-	int corr, dcd;
+#if 0
+ 	int16_t eq;
+	int32_t gardner;
+	int corr;
+#endif
+        int dcd;
 
 	samples = alloca((nsamples + s->firlen) * sizeof(samples[0]));
 	audioread(s->chan, samples, nsamples + s->firlen, s->stime);
@@ -448,8 +454,8 @@
 		mids += s->dcoffs;
 		nexts += s->dcoffs;
 		/* sample clock recovery */
-		gardner = ((nexts > 0 ? 1 : -1) - (curs > 0 ? 1 : -1)) * mids;
 #if 0
+		gardner = ((nexts > 0 ? 1 : -1) - (curs > 0 ? 1 : -1)) * mids;
 		eq = equalizer(s, mids, nexts);
 #endif
 		s->pll += s->pllinc;
@@ -531,7 +537,7 @@
 	float coeff[FILTEROVER][MAXFIRLEN];
 	float pulseen[FILTEROVER];
 	double tmul;
-	float max1, max2, t, at, f1, f2;
+	float max1, max2, t, f1;
 	int i, j;
 
 	s->firlen = (samplerate * FILTERSPANBITS + s->bps - 1) / s->bps;
--- a/fsk/modempsp.c
+++ b/fsk/modempsp.c
@@ -344,8 +344,10 @@
 {
 	int16_t *samples;
  	int16_t curs, nexts, mids;
+#if 0
 	int32_t gardner;
 	int corr;
+#endif
 
 	samples = alloca((nsamples + s->firlen) * sizeof(samples[0]));
 	audioread(s->chan, samples, nsamples + s->firlen, s->stime);
@@ -359,7 +361,9 @@
 		curs = filter(s, samples, s->pll);
 		mids = filter(s, samples, s->pll+s->pllinc/2);
 		nexts = filter(s, samples, s->pll+s->pllinc);
+#if 0
 		gardner = ((nexts > 0 ? 1 : -1) - (curs > 0 ? 1 : -1)) * mids;
+#endif
 		s->pll += s->pllinc;
 #if 0
 		corr = (gardner * s->pllinc) >> 20;
@@ -396,7 +400,7 @@
         struct demodstate *s = (struct demodstate *)state;
 	float coeff[FILTEROVER][MAXFIRLEN];
 	double tmul;
-	float max1, max2, t, at, f1, f2, f3;
+	float max1, max2, t;
 	int i, j;
 
 	s->firlen = (samplerate * FILTERSPANBITS + s->bps - 1) / s->bps;
--- a/fsk/modemeq.c
+++ b/fsk/modemeq.c
@@ -140,6 +140,7 @@
 	return fir(s->filter[WHICHFILTER(ph)], samples + WHICHSAMPLE(ph), s->firlen);
 }
 
+#if 0
 static int16_t equalizer(struct demodstate *s, int16_t s1, int16_t s2)
 {
 	int16_t target;
@@ -160,6 +161,7 @@
  printf("%5d %5d %5d %5d %5d\n", s->eqf[0], s->eqf[1], s->eqf[2], s->eqf[3], s->eqf[4]);
 	return sum;
 }
+#endif
 
 static const struct modemparams demodparams[] = {
         { "bps", "Bits/s", "Bits per second", "9600", MODEMPAR_NUMERIC, { n: { 4800, 38400, 100, 1200 } } },
@@ -270,11 +272,14 @@
 static void demodrx(struct demodstate *s, unsigned nsamples)
 {
 	int16_t *samples;
- 	int16_t curs, nexts, mids, xs, eqs;
-	int32_t gardner;
-	unsigned int d, descx;
+ 	int16_t curs, nexts, mids, eqs;
+	unsigned int descx;
 	unsigned char ch[3];
-	int corr, dcd;
+	int dcd;
+#if 0
+	int32_t gardner;
+	int corr;
+#endif
 
 	samples = alloca((nsamples + s->firlen) * sizeof(samples[0]));
 	audioread(s->chan, samples, nsamples + s->firlen, s->stime);
@@ -288,8 +293,8 @@
 		curs = filter(s, samples, s->pll);
 		mids = filter(s, samples, s->pll+s->pllinc/2);
 		nexts = filter(s, samples, s->pll+s->pllinc);
-		gardner = ((nexts > 0 ? 1 : -1) - (curs > 0 ? 1 : -1)) * mids;
 #if 0
+		gardner = ((nexts > 0 ? 1 : -1) - (curs > 0 ? 1 : -1)) * mids;
 		eqs = equalizer(s, mids, nexts);
 #endif
 		eqs = filter_eq(s, curs, mids);
@@ -384,7 +389,7 @@
 	float coeff[FILTEROVER][MAXFIRLEN];
 	float pulseen[FILTEROVER];
 	double tmul;
-	float max1, max2, t, at, f1, f2;
+	float max1, max2, t, f1;
 	int i, j;
 
 	s->firlen = (samplerate * FILTERSPANBITS + s->bps - 1) / s->bps;
--- a/afsk/modem.c
+++ b/afsk/modem.c
@@ -277,7 +277,8 @@
         unsigned int phasecorr = phinc >> 4;
         unsigned int totsamp = ((12 * phinc) >> 16) + RXFILTLEN;
         unsigned int phase, nr;
-        int oldv, newv, midv, thv;
+        int oldv, newv, thv;
+        int midv = 0;
 
         samples = alloca(totsamp * sizeof(samples[0]));
         audioread(s->chan, samples, totsamp, s->rxphase >> 16);
--- a/pammodem/genpamtbl.c
+++ b/pammodem/genpamtbl.c
@@ -300,8 +300,11 @@
 static void genrxfilt(FILE *f)
 {
 	float coeff[RXFILTLEN * RXFILTOVER];
-	double tmul, at, t, f1, f2;
+	double tmul, f1, f2;
 	int i, j;
+#if 0
+        double at, t;
+#endif
 
 	tmul = 1.0 * BITRATE / RXFILTOVER / SAMPLERATE;
 #if 1