Allow Proxy creation without a set TraceCtx

thunder/core/proxies.py

@@ -82,6 +82,8 @@ def is_proxy_name_available(name: None | str = None):
 
 def make_proxy_name(*, name: None | str = None, prefix: None | str = None) -> str:
     trc = get_tracectx()
+    if trc is None:
+        return name
     return trc.make_name(name=name, prefix=prefix)
 
 
@@ -1421,7 +1423,7 @@ def __init__(
         shape: ShapeLike | None = None,
         device: devices.Device | None = None,
         dtype: dtypes.dtype | None = None,
-        requires_grad: bool | None = None,
+        requires_grad: bool = False,
         grad: TensorProxy | None = None,
         prefix: None | str = None,
         distparallel_type: DistParallelType | None = None,

thunder/tests/test_core.py

@@ -3118,16 +3118,27 @@ def test_debug_options():
     assert dill.dumps(dict(DebugOptions.__dict__)) == initial_state
 
 
+def test_default_tensor_proxy():
+    from thunder.core.proxies import TensorProxy
+    from thunder.core.dtypes import float32
+    from thunder.core.devices import cpu
+
+    # It should be possible to create a TensorProxy with default values for all
+    # optional arguments
+    t = TensorProxy(shape=(1,), device=cpu, dtype=float32)
+    assert not t.requires_grad
+    assert t.device == cpu
+    assert t.dtype == float32
+
+
 def test_proxy_same_name():
     from thunder.core.proxies import TensorProxy
-    from thunder.core.trace import detached_trace
     from thunder.core.dtypes import float32
     from thunder.core.devices import cpu
 
-    with detached_trace():
-        t = TensorProxy(name="test", shape=(1,), device=cpu, dtype=float32, requires_grad=True)
-        with pytest.raises(RuntimeError, match="already used"):
-            t2 = TensorProxy(name="test", shape=(1,), device=cpu, dtype=float32, requires_grad=True)
+    t = TensorProxy(name="test", shape=(1,), device=cpu, dtype=float32)
+    with pytest.raises(RuntimeError, match="already used"):
+        t2 = TensorProxy(name="test", shape=(1,), device=cpu, dtype=float32)
 
 
 def test_save_trace():