Simple unit testing for C

driver.c

#include <stdio.h>
#include <stdlib.h>
#include "module.h"
#include "utest.h"

extern UTEST(module);

UTEST_MAIN()
{
	utest_module();
}

int main(void)
{
	utest();

	return 0;
}

Makefile

CC = gcc
CPPFLAGS += -D_GNU_SOURCE 
CFLAGS += -O0 -g -Wall -Wextra

SRCS = driver.c module.c
OBJS = $(SRCS:.c=.o)

all: utest

utest: $(OBJS) 
	$(CC) -o $@ $^ $(LDFLAGS) $(IMPORTS)

clean:
	rm -f utest $(OBJS)

driver.o: module.h utest.h
module.o: module.h utest.h

.PHONY: all clean

module.c

#include "module.h"
#include "utest.h"

int A(int a, int b)
{
	return a + b;
}

int B(int a, int b)
{
	return a - b;
}

UTEST(module)
{
	check_equal(A(1, 2), 3);
	check_equal(A(-2, 6), 4);
	check_equal(A(-4, -1), -5);
	check_equal(A(9, 0), 8 + 1);

	check_equal(B(4, 5), -1);
	check_equal(B(5, A(3, 4)), -5);
	check_equal(B(A(2, 1), A(1, 2)), 0);
}

module.h

#ifndef MODULE_H
#define MODULE_H

int A(int a, int b);
int B(int a, int b);

#endif // MODULE_H

utest.h

#ifndef UTEST_H
#define UTEST_H

#include <stdio.h>
#include <stdlib.h>

#define check_equal(a, b) \
{ \
	utest_count++; \
	if ((a) != (b)) { \
		fprintf(stderr, "Test %3u failed: %s != %s\n", utest_count, #a, #b); \
		utest_count_failed++; \
	} \
}

#define UTEST(name) \
void utest_##name(void)

#define UTEST_MAIN() \
unsigned int utest_count; \
unsigned int utest_count_failed; \
UTEST(main)

#define utest_init() \
{ \
	utest_count = utest_count_failed = 0; \
}

#define utest_exit() \
{ \
	fprintf(stderr, "%u of %u tests completed successfully\n",\
			utest_count - utest_count_failed, utest_count); \
	if (utest_count_failed) \
		abort(); \
}

#define utest() \
{ \
	utest_init(); \
	utest_main(); \
	utest_exit(); \
}

extern unsigned int utest_count;
extern unsigned int utest_count_failed;

#endif // UTEST_H