add jt.Var constructor

python/jittor/test/test_array.py

@@ -132,6 +132,14 @@ class TestArray(unittest.TestCase):
         a = jt.array([1,2,3], dtype=jt.NanoString("float32"))
         a = jt.array([1,2,3], dtype=jt.float32)
 
+    def test_var(self):
+        a = jt.Var([1,2,3])
+        b = jt.Var([1,2,3], "float32")
+        assert a.dtype == "int32"
+        assert b.dtype == "float32"
+        assert (a.numpy() == [1,2,3]).all()
+        assert (b.numpy() == [1,2,3]).all()
+
 
 
 if __name__ == "__main__":

src/var_holder.cc

@@ -15,6 +15,7 @@
 #include "graph.h"
 #include "update_queue.h"
 #include "mem/allocator/cuda_dual_allocator.h"
+#include "ops/op_register.h"
 
 namespace jittor {
 
@@ -61,7 +62,23 @@ VarHolder::VarHolder(VarHolder* v) : var(v->var) {
     operator delete(v);
 }
 
+static auto make_array_from_pyobj = get_op_info("array")
+    .get_constructor<VarPtr, PyObject*>();
+static auto make_unary = get_op_info("unary")
+    .get_constructor<VarPtr, Var*, NanoString>();
+
+VarHolder::VarHolder(PyObject* obj, NanoString dtype) {
+    auto vp = make_array_from_pyobj(obj);
+    if (dtype != ns_void)
+        vp = make_unary(vp, dtype);
+    var = vp.ptr;
+    vp.ptr = nullptr;
+    add_hold_vars(this);
+}
+
+
 VarHolder::~VarHolder() {
+    if (PREDICT_BRANCH_NOT_TAKEN(!var)) return;
     hold_vars.erase(iter);
     var->release_both_liveness();
 }

src/var_holder.h

@@ -28,6 +28,8 @@ struct ItemData {
     NanoString dtype;
 };
 
+typedef struct _object PyObject;
+
 // @pyjt(Var)
 // @attrs(heaptype)
 struct VarHolder {
@@ -37,6 +39,8 @@ struct VarHolder {
     VarHolder(VarPtr&& v);
     // will move and delete v
     VarHolder(VarHolder* v);
+    // @pyjt(__init__)
+    VarHolder(PyObject* v, NanoString dtype=ns_void);
     // @pyjt(__dealloc__)
     ~VarHolder();
     string to_string();