zig/test/standalone/link_common_symbols/main.zig

const std = @import("std");
const expect = std.testing.expect;

extern fn incr_i() void;
extern fn add_to_i_and_j(x: c_int) c_int;

test "import C common symbols" {
    incr_i();
    const res = add_to_i_and_j(2);
    try expect(res == 5);
}