Automated rollback of commit 356b4db

PiperOrigin-RevId: 407865521

Author: tensorflower-gardener

site/en/guide/function.ipynb

@@ -1202,9 +1202,10 @@
         "correct_a = leaky_function(tf.constant(1))\n",
         "\n",
         "print(correct_a.numpy())  # Good - value obtained from function's returns\n",
-        "with assert_raises(AttributeError):\n",
+        "try:\n",
         "  x.numpy()  # Bad - tensor leaked from inside the function, cannot be used here\n",
-        "print(x)"
+        "except AttributeError as expected:\n",
+        "  print(expected)"
       ]
     },
     {
@@ -1233,9 +1234,10 @@
         "correct_a = leaky_function(tf.constant(1))\n",
         "\n",
         "print(correct_a.numpy())  # Good - value obtained from function's returns\n",
-        "with assert_raises(AttributeError):\n",
+        "try:\n",
         "  x.numpy()  # Bad - tensor leaked from inside the function, cannot be used here\n",
-        "print(x)\n",
+        "except AttributeError as expected:\n",
+        "  print(expected)\n",
         "\n",
         "@tf.function\n",
         "def captures_leaked_tensor(b):\n",
@@ -1280,6 +1282,64 @@
         "  external_object.field = a  # Bad - leaks tensor"
       ]
     },
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "g-XVQcD-wf5K"
+      },
+      "source": [
+        "### Recursive tf.functions are not supported\n",
+        "\n",
+        "Recursive `Function`s are not supported and could cause infinite loops. For example,"
+      ]
+    },
+    {
+      "cell_type": "code",
+      "execution_count": null,
+      "metadata": {
+        "id": "QSN-T1m5EFcR"
+      },
+      "outputs": [],
+      "source": [
+        "@tf.function\n",
+        "def recursive_fn(n):\n",
+        "  if n > 0:\n",
+        "    return recursive_fn(n - 1)\n",
+        "  else:\n",
+        "    return 1\n",
+        "\n",
+        "with assert_raises(Exception):\n",
+        "  recursive_fn(tf.constant(5))  # Bad - maximum recursion error."
+      ]
+    },
+    {
+      "cell_type": "markdown",
+      "metadata": {
+        "id": "LyRyooKGUxNV"
+      },
+      "source": [
+        "Even if a recursive `Function` seems to work, the python function will be traced multiple times and could have performance implication. For example,"
+      ]
+    },
+    {
+      "cell_type": "code",
+      "execution_count": null,
+      "metadata": {
+        "id": "7FlmTqfMUwmT"
+      },
+      "outputs": [],
+      "source": [
+        "@tf.function\n",
+        "def recursive_fn(n):\n",
+        "  if n > 0:\n",
+        "    print('tracing')\n",
+        "    return recursive_fn(n - 1)\n",
+        "  else:\n",
+        "    return 1\n",
+        "\n",
+        "recursive_fn(5)  # Warning - multiple tracings"
+      ]
+    },
     {
       "cell_type": "markdown",
       "metadata": {