Avoid using empty macro arguments.

These are not supported by all compilers (gcc 2.95 but also older SPARC
compilers, see gcc bug #33304 for example), and there is no real need for them.
One use of this feature remains in libavdevice/v4l2.c which can't be
replaced quite as easily.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

libavcodec/mss1.c

@@ -60,7 +60,7 @@ static void arith_normalise(ArithCoder *c)
     }
 }
 
-ARITH_GET_BIT()
+ARITH_GET_BIT(arith)
 
 static int arith_get_bits(ArithCoder *c, int bits)
 {
@@ -105,7 +105,7 @@ static int arith_get_prob(ArithCoder *c, int16_t *probs)
     return sym;
 }
 
-ARITH_GET_MODEL_SYM()
+ARITH_GET_MODEL_SYM(arith)
 
 static void arith_init(ArithCoder *c, GetBitContext *gb)
 {

libavcodec/mss12.h

@@ -99,8 +99,8 @@ int ff_mss12_decode_init(MSS12Context *c, int version,
                          SliceContext *sc1, SliceContext *sc2);
 int ff_mss12_decode_end(MSS12Context *ctx);
 
-#define ARITH_GET_BIT(VERSION)                                          \
-static int arith ## VERSION ## _get_bit(ArithCoder *c)                  \
+#define ARITH_GET_BIT(prefix)                                           \
+static int prefix ## _get_bit(ArithCoder *c)                            \
 {                                                                       \
     int range = c->high - c->low + 1;                                   \
     int bit   = 2 * c->value - c->low >= c->high;                       \
@@ -110,22 +110,22 @@ static int arith ## VERSION ## _get_bit(ArithCoder *c)                  \
     else                                                                \
         c->high = c->low + (range >> 1) - 1;                            \
                                                                         \
-    arith ## VERSION ## _normalise(c);                                  \
+    prefix ## _normalise(c);                                            \
                                                                         \
     return bit;                                                         \
 }
 
-#define ARITH_GET_MODEL_SYM(VERSION)                                    \
-static int arith ## VERSION ## _get_model_sym(ArithCoder *c, Model *m)  \
+#define ARITH_GET_MODEL_SYM(prefix)                                     \
+static int prefix ## _get_model_sym(ArithCoder *c, Model *m)            \
 {                                                                       \
     int idx, val;                                                       \
                                                                         \
-    idx = arith ## VERSION ## _get_prob(c, m->cum_prob);                \
+    idx = prefix ## _get_prob(c, m->cum_prob);                          \
                                                                         \
     val = m->idx2sym[idx];                                              \
     ff_mss12_model_update(m, idx);                                      \
                                                                         \
-    arith ## VERSION ## _normalise(c);                                  \
+    prefix ## _normalise(c);                                            \
                                                                         \
     return val;                                                         \
 }

libavcodec/mss2.c

@@ -54,7 +54,7 @@ static void arith2_normalise(ArithCoder *c)
     }
 }
 
-ARITH_GET_BIT(2)
+ARITH_GET_BIT(arith2)
 
 /* L. Stuiver and A. Moffat: "Piecewise Integer Mapping for Arithmetic Coding."
  * In Proc. 8th Data Compression Conference (DCC '98), pp. 3-12, Mar. 1998 */
@@ -127,7 +127,7 @@ static int arith2_get_prob(ArithCoder *c, int16_t *probs)
     return i;
 }
 
-ARITH_GET_MODEL_SYM(2)
+ARITH_GET_MODEL_SYM(arith2)
 
 static int arith2_get_consumed_bytes(ArithCoder *c)
 {

libswresample/x86/swresample_x86.c

@@ -21,14 +21,14 @@
 #include "libswresample/swresample_internal.h"
 #include "libswresample/audioconvert.h"
 
-#define PROTO(pre, in, out, cap) void ff ## pre ## _ ##in## _to_ ##out## _a_ ##cap(uint8_t **dst, const uint8_t **src, int len);
+#define PROTO(pre, in, out, cap) void ff ## pre ## in## _to_ ##out## _a_ ##cap(uint8_t **dst, const uint8_t **src, int len);
 #define PROTO2(pre, out, cap) PROTO(pre, int16, out, cap) PROTO(pre, int32, out, cap) PROTO(pre, float, out, cap)
 #define PROTO3(pre, cap) PROTO2(pre, int16, cap) PROTO2(pre, int32, cap) PROTO2(pre, float, cap)
 #define PROTO4(pre) PROTO3(pre, mmx) PROTO3(pre, sse) PROTO3(pre, sse2) PROTO3(pre, ssse3) PROTO3(pre, sse4) PROTO3(pre, avx)
-PROTO4()
-PROTO4(_pack_2ch)
-PROTO4(_pack_6ch)
-PROTO4(_unpack_2ch)
+PROTO4(_)
+PROTO4(_pack_2ch_)
+PROTO4(_pack_6ch_)
+PROTO4(_unpack_2ch_)
 
 av_cold void swri_audio_convert_init_x86(struct AudioConvert *ac,
                                  enum AVSampleFormat out_fmt,