Add tests for `clock`, `times`, and `getrusage`. (#177)

tests/general/clocks.c

@@ -0,0 +1,43 @@
+#include <time.h>
+#include <sys/resource.h>
+#include <sys/times.h>
+#include <assert.h>
+
+static void test_clock(void) {
+    clock_t a = clock();
+    clock_t b = clock();
+    assert(a != -1);
+    assert(b != -1);
+    assert(a > 0);
+    assert(b >= a);
+}
+
+static void test_times(void) {
+    struct tms before;
+    struct tms after;
+    clock_t a = times(&before);
+    clock_t b = times(&after);
+    assert(a != -1);
+    assert(b != -1);
+    assert(b >= a);
+    assert(after.tms_utime >= before.tms_utime);
+}
+
+static void test_getrusage(void) {
+    struct rusage before;
+    struct rusage after;
+    int a = getrusage(RUSAGE_SELF, &before);
+    int b = getrusage(RUSAGE_SELF, &after);
+    assert(a != -1);
+    assert(b != -1);
+    assert(after.ru_utime.tv_sec >= before.ru_utime.tv_sec);
+    assert(after.ru_utime.tv_sec != before.ru_utime.tv_sec ||
+	   after.ru_utime.tv_usec >= before.ru_utime.tv_usec);
+}
+
+int main(void) {
+    test_clock();
+    test_times();
+    test_getrusage();
+    return 0;
+}

tests/general/clocks.c.options

@@ -0,0 +1 @@
+-D_WASI_EMULATED_PROCESS_CLOCKS -lwasi-emulated-process-clocks