test/ffi-test-lib.c

1/* Tiny shared library for FFI dlopen smoke tests.

2 *

3 * Compiled during test with:

4 * cc -shared -fPIC -o libffi-test.so ffi-test-lib.c

5 */

7#include <string.h>

8#include <stdlib.h>

10/* Basic arithmetic — tests int and double marshaling */

11int add_ints(int a, int b)

12{

13 return a + b;

14}

16double multiply_doubles(double a, double b)

17{

18 return a * b;

19}

21/* Mixed types — tests cross-type signatures */

22double int_to_double(int x)

23{

24 return (double)x * 2.5;

25}

27int double_to_int(double x)

28{

29 return (int)x;

30}

32/* String handling — tests string marshaling across dlopen */

33int string_length(const char *s)

34{

35 return (int)strlen(s);

36}

38/* Returns a static string — tests string return */

39const char *greeting(void)

40{

41 return "hello from ffi-test-lib";

42}

44/* Pointer operations — tests pointer passing */

45void fill_buffer(int *buf, int count, int value)

46{

47 for (int i = 0; i < count; i++) {

48 buf[i] = value + i;

49 }

50}

52int sum_buffer(const int *buf, int count)

53{

54 int total = 0;

55 for (int i = 0; i < count; i++) {

56 total += buf[i];

57 }

58 return total;

59}

61/* Struct-by-value — tests dyncall struct passing */

62typedef struct {

63 double x;

64 double y;

65} Point;

67Point make_point(double x, double y)

68{

69 Point p = { x, y };

70 return p;

71}

73double point_distance(Point a, Point b)

74{

75 double dx = b.x - a.x;

76 double dy = b.y - a.y;

77 return dx * dx + dy * dy; /* squared distance, avoids needing sqrt */

78}

80/* Callback test — calls a function pointer */

81typedef int (*IntBinaryFn)(int, int);

83int apply_fn(IntBinaryFn fn, int a, int b)

84{

85 return fn(a, b);

86}