Avoid warnings on all-zero static struct entries.

src/libsigrok-internal.h

@@ -143,6 +143,15 @@
 	libusb_handle_events_timeout(ctx, tv)
 #endif
 
+/* Static definitions of structs ending with an all-zero entry are a
+ * problem when compiling with -Wmissing-field-initializers: GCC
+ * suppresses the warning only with { 0 }, clang wants { } */
+#ifdef __clang__
+#define ALL_ZERO { }
+#else
+#define ALL_ZERO { 0 }
+#endif
+
 struct sr_context {
 #ifdef HAVE_LIBUSB_1_0
 	libusb_context *libusb_ctx;

src/output/ascii.c

@@ -235,7 +235,7 @@ static int cleanup(struct sr_output *o)
 
 static struct sr_option options[] = {
 	{ "width", "Width", "Number of samples per line", NULL, NULL },
-	{ 0 }
+	ALL_ZERO
 };
 
 static const struct sr_option *get_options(void)

src/output/bits.c

@@ -221,7 +221,7 @@ static int cleanup(struct sr_output *o)
 
 static struct sr_option options[] = {
 	{ "width", "Width", "Number of samples per line", NULL, NULL },
-	{ 0 }
+	ALL_ZERO
 };
 
 static const struct sr_option *get_options(void)

src/output/hex.c

@@ -235,7 +235,7 @@ static int cleanup(struct sr_output *o)
 
 static struct sr_option options[] = {
 	{ "width", "Width", "Number of samples per line", NULL, NULL },
-	{ 0 }
+	ALL_ZERO
 };
 
 static const struct sr_option *get_options(void)

src/output/wav.c

@@ -336,7 +336,7 @@ static int cleanup(struct sr_output *o)
 
 static struct sr_option options[] = {
 	{ "scale", "Scale", "Scale values by factor", NULL, NULL },
-	{ 0 }
+	ALL_ZERO
 };
 
 static const struct sr_option *get_options(void)