Proper clock initialization stricter tests

integration_tests/test_random.py

@@ -53,13 +53,31 @@ def test_weibullvariate():
     print(r)
 
 def test_seed():
+    random.seed()
+    t6: f64 = random.random()
     random.seed(123)
     t1: f64
     t1 = random.random()
     random.seed(321)
     t2: f64
     t2 = random.random()
+    random.seed(123)
+    t3: f64
+    t3 = random.random()
+    random.seed(0)
+    t4: f64
+    t4 = random.random()
+    random.seed(0)
+    t5: f64
+    t5 = random.random()
+    random.seed()
+    t7: f64 = random.random()
     assert t1 != t2
+    assert t1 == t3
+    assert t1 != t4
+    assert t1 != t5
+    assert t4 == t5
+    assert t6 != t7
 
 def check():
     test_random()

src/libasr/runtime/lfortran_intrinsics.c

@@ -96,13 +96,14 @@ LFORTRAN_API void _lfortran_random_number(int n, double *v)
     }
 }
 
-LFORTRAN_API void _lfortran_init_random(unsigned seed) 
+LFORTRAN_API void _lfortran_init_random_seed(unsigned seed)
 {
-    if (seed == 0) {
-        srand((unsigned int)clock());
-    } else {
-        srand(seed);
-    }
+    srand(seed);
+}
+
+LFORTRAN_API void _lfortran_init_random_clock()
+{
+    srand((unsigned int)clock());
 }
 
 LFORTRAN_API double _lfortran_random()

src/libasr/runtime/lfortran_intrinsics.h

@@ -67,7 +67,8 @@ typedef double _Complex double_complex_t;
 
 LFORTRAN_API double _lfortran_sum(int n, double *v);
 LFORTRAN_API void _lfortran_random_number(int n, double *v);
-LFORTRAN_API void _lfortran_init_random(unsigned seed);
+LFORTRAN_API void _lfortran_init_random_clock();
+LFORTRAN_API void _lfortran_init_random_seed(unsigned seed);
 LFORTRAN_API double _lfortran_random();
 LFORTRAN_API int _lfortran_randrange(int lower, int upper);
 LFORTRAN_API int _lfortran_random_int(int lower, int upper);

src/runtime/random.py

@@ -32,15 +32,28 @@ def random() -> f64:
 def _lfortran_random() -> f64:
     pass
 
+@overload
+def seed() -> None:
+    """
+    Initializes the random number generator.
+    """
+    _lfortran_init_random_clock()
+    return
+
+@overload
 def seed(seed: i32) -> None:
     """
     Initializes the random number generator.
     """
-    _lfortran_init_random(seed)
+    _lfortran_init_random_seed(seed)
     return
 
 @ccall
-def _lfortran_init_random(seed: i32) -> None:
+def _lfortran_init_random_clock() -> None:
+    pass
+
+@ccall
+def _lfortran_init_random_seed(seed: i32) -> None:
     pass
 
 def randrange(lower: i32, upper: i32) -> i32: