Add empty test_bits1to14.c to the build and simply Makefiles a bit

Issue #3

Makefile

@@ -20,10 +20,8 @@ all: libdcf77.so dcf77pi dcf77pi-analyze readpin
 
 hdrlib=input.h decode_time.h decode_alarm.h setclock.h mainloop.h \
 	bits1to14.h calendar.h
-srclib=input.c decode_time.c decode_alarm.c setclock.c mainloop.c \
-	bits1to14.c calendar.c
-objlib=input.o decode_time.o decode_alarm.o setclock.o mainloop.o \
-	bits1to14.o calendar.o
+srclib=${hdrlib:.h=.c}
+objlib=${hdrlib:.h=.o}
 objbin=dcf77pi.o dcf77pi-analyze.o readpin.o
 
 input.o: input.h

tests/Makefile

@@ -3,20 +3,27 @@
 
 .PHONY: all clean test
 
+objbin=testcentury.o test_bits1to14.o
+exebin=${objbin:.o=}
+
 all: test
-test: testcentury
+test: $(exebin)
 	./testcentury
+	./test_bits1to14
 
 PREFIX?=.
 ETCDIR?=etc/dcf77pi
 CFLAGS+=-Wall -D_POSIX_C_SOURCE=200809L -DETCDIR=\"$(PREFIX)/$(ETCDIR)\" \
 	-g -std=c99
-objbin=testcentury.o
 
 testcentury.o: ../calendar.h
 	$(CC) -fpic $(CFLAGS) -I.. -c testcentury.c -o $@
 testcentury: testcentury.o ../calendar.o
 	$(CC) -o $@ testcentury.o ../calendar.o
+test_bits1to14.o: ../bits1to14.h
+	$(CC) -fpic $(CFLAGS) -I.. -c test_bits1to14.c -o $@
+test_bits1to14: test_bits1to14.o ../bits1to14.o
+	$(CC) -o $@ test_bits1to14.o ../bits1to14.o
 
 clean:
-	rm -f $(objbin) testcentury
+	rm -f $(objbin) $(exebin)

tests/test_bits1to14.c

@@ -0,0 +1,13 @@
+// Copyright 2017 René Ladan
+// SPDX-License-Identifier: BSD-2-Clause
+
+#include "bits1to14.h"
+
+#include <stdio.h>
+#include <sysexits.h>
+
+int
+main(int argc, char *argv[])
+{
+	return EX_OK;
+}