[export] Refactor the imports for the public API of jax.experimental.export

Previously we used `from jax.experimental.export import export` and
`export.export(fun)`. Now we want to add the public API directly
to `jax.experimental.export`, for the following desired usage:

```
from jax.experimental import export

exp: export.Exported = export.export(fun)
ser: bytearray = export.serialize(exp)
exp1: export.Exported = export.deserialized(ser)
export.call(exp1)
```

This change requires changing the type of
`jax.experimental.export.export` from a
module to a function. This confuses
pytype for the targets with strict type checking,
which is why I attempt to make this change
atomically throughout the internal code base.

In order to support backwards compatibility with
OSS packages, this change also includes explicit
JAX version checks in several OSS packages, and
also adds to the `export` function the attributes
that the old export module had.

PiperOrigin-RevId: 596563481

CHANGELOG.md

@@ -9,6 +9,7 @@ Remember to align the itemized text with the first line of an item within a list
 ## jax 0.4.24
 
 * Changes
+
   * JAX lowering to StableHLO does not depend on physical devices anymore.
     If your primitive wraps custom_paritioning or JAX callbacks in the lowering
     rule i.e. function passed to `rule` parameter of `mlir.register_lowering` then add your
@@ -27,6 +28,10 @@ Remember to align the itemized text with the first line of an item within a list
     ({jax-issue}`#19231`; note that this may result in user-visible behavior
     changes); improved the error messages for inconclusive inequality comparisons
     ({jax-issue}`#19235`).
+  * Refactored the API for `jax.experimental.export`. Instead of
+    `from jax.experimental.export import export` you should use now
+    `from jax.experimental import export`. The old way of importing will
+    continue to work for a deprecation period of 3 months.
 * Deprecations & Removals
   * A number of previously deprecated functions have been removed, following a
     standard 3+ month deprecation cycle (see {ref}`api-compatibility`).

jax/_src/internal_test_util/export_back_compat_test_util.py

@@ -83,7 +83,7 @@ from numpy import array, float32
 
 import jax
 from jax import tree_util
-from jax.experimental.export import export
+from jax.experimental import export
 
 from jax.experimental import pjit
 

jax/experimental/export/BUILD

@@ -22,7 +22,6 @@ load("@rules_python//python:defs.bzl", "py_library")
 
 licenses(["notice"])
 
-# Please add new users to :australis_users.
 package(
     default_applicable_licenses = [],
     default_visibility = ["//visibility:private"],
@@ -31,7 +30,8 @@ package(
 py_library(
     name = "export",
     srcs = [
-        "export.py",
+        "__init__.py",
+        "_export.py",
         "serialization.py",
         "serialization_generated.py",
         "shape_poly.py",

jax/experimental/export/__init__.py

@@ -12,3 +12,21 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ==============================================================================
+
+from jax.experimental.export._export import (
+    minimum_supported_serialization_version,
+    maximum_supported_serialization_version,
+    Exported,
+    export,
+    call_exported,  # TODO: deprecate
+    call,
+    DisabledSafetyCheck,
+    default_lowering_platform,
+
+    symbolic_shape,
+    args_specs,
+)
+from jax.experimental.export.serialization import (
+    serialize,
+    deserialize,
+)

jax/experimental/export/_export.py

@@ -24,6 +24,7 @@ import functools
 import itertools
 import re
 from typing import Any, Callable, Optional, TypeVar, Union
+import warnings
 
 from absl import logging
 import numpy as np
@@ -57,6 +58,20 @@ zip = util.safe_zip
 
 DType = Any
 Shape = jax._src.core.Shape
+# The values of input and output sharding from the lowering.
+LoweringSharding = Union[sharding.XLACompatibleSharding, pxla.UnspecifiedValue]
+
+# None means unspecified sharding
+Sharding = Union[xla_client.HloSharding, None]
+
+# See https://github.com/google/jax/blob/main/jax/experimental/jax2tf/README.md#native-serialization-versions
+# for a description of the different versions.
+minimum_supported_serialization_version = 6
+maximum_supported_serialization_version = 9
+
+_VERSION_START_SUPPORT_SHAPE_ASSERTIONS = 7
+_VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS = 9
+
 
 class DisabledSafetyCheck:
   """A safety check should be skipped on (de)serialization.
@@ -117,19 +132,6 @@ class DisabledSafetyCheck:
   def __hash__(self) -> int:
     return hash(self._impl)
 
-# See https://github.com/google/jax/blob/main/jax/experimental/jax2tf/README.md#native-serialization-versions
-# for a description of the different versions.
-minimum_supported_serialization_version = 6
-maximum_supported_serialization_version = 9
-
-_VERSION_START_SUPPORT_SHAPE_ASSERTIONS = 7
-_VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS = 9
-
-# The values of input and output sharding from the lowering.
-LoweringSharding = Union[sharding.XLACompatibleSharding, pxla.UnspecifiedValue]
-
-# None means unspecified sharding
-Sharding = Union[xla_client.HloSharding, None]
 
 @dataclasses.dataclass(frozen=True)
 class Exported:
@@ -1052,7 +1054,7 @@ def _export_native_vjp(primal_fun, primal: Exported) -> Exported:
 
 ### Calling the exported function
 
-def call_exported(exported: Exported) -> Callable[..., jax.Array]:
+def call(exported: Exported) -> Callable[..., jax.Array]:
   if not isinstance(exported, Exported):
     raise ValueError(
       "The exported argument must be an export.Exported. "
@@ -1107,6 +1109,7 @@ def call_exported(exported: Exported) -> Callable[..., jax.Array]:
     return exported.out_tree.unflatten(res_flat)
   return f_imported
 
+call_exported = call
 
 # A JAX primitive for invoking a serialized JAX function.
 call_exported_p = core.Primitive("call_exported")
@@ -1307,3 +1310,30 @@ def wrap_with_sharding(ctx: mlir.LoweringRuleContext,
     return x
   return mlir.wrap_with_sharding_op(
     ctx, x, x_aval, x_sharding.to_proto())
+
+# TODO(necula): Previously, we had `from jax.experimental.export import export`
+# Now we want to simplify the usage, and export the public APIs directly
+# from `jax.experimental.export` and now `jax.experimental.export.export`
+# refers to the `export` function. Since there may still be users of the
+# old API in other packages, we add the old public API as attributes of the
+# exported function. We will clean this up after a deprecation period.
+def wrap_with_deprecation_warning(f):
+  msg = (f"You are using function `{f.__name__}` from "
+         "`jax.experimental.export.export`. You should instead use it directly "
+         "from `jax.experimental.export`. Instead of "
+         "`from jax.experimental.export import export` you should use "
+         "`from jax.experimental import export`.")
+  def wrapped_f(*args, **kwargs):
+    warnings.warn(msg, DeprecationWarning)
+    return f(*args, **kwargs)
+  return wrapped_f
+
+export.export = wrap_with_deprecation_warning(export)
+export.Exported = Exported
+export.call_exported = wrap_with_deprecation_warning(call_exported)
+export.DisabledSafetyCheck = DisabledSafetyCheck
+export.default_lowering_platform = wrap_with_deprecation_warning(default_lowering_platform)
+export.symbolic_shape = wrap_with_deprecation_warning(symbolic_shape)
+export.args_specs = wrap_with_deprecation_warning(args_specs)
+export.minimum_supported_serialization_version = minimum_supported_serialization_version
+export.maximum_supported_serialization_version = maximum_supported_serialization_version

jax/experimental/export/serialization.py

@@ -29,8 +29,10 @@ from jax._src import dtypes
 from jax._src import effects
 from jax._src import tree_util
 from jax._src.lib import xla_client
-from jax.experimental.export import export
 from jax.experimental.export import serialization_generated as ser_flatbuf
+from jax.experimental.export import _export
+from jax.experimental import export
+
 import numpy as np
 
 T = TypeVar("T")
@@ -359,7 +361,7 @@ def _deserialize_aval(aval: ser_flatbuf.AbstractValue) -> core.AbstractValue:
 
 
 def _serialize_sharding(
-    builder: flatbuffers.Builder, s: export.Sharding
+    builder: flatbuffers.Builder, s: _export.Sharding
 ) -> int:
   proto = None
   if s is None:
@@ -376,7 +378,7 @@ def _serialize_sharding(
   return ser_flatbuf.ShardingEnd(builder)
 
 
-def _deserialize_sharding(s: ser_flatbuf.Sharding) -> export.Sharding:
+def _deserialize_sharding(s: ser_flatbuf.Sharding) -> _export.Sharding:
   kind = s.Kind()
   if kind == ser_flatbuf.ShardingKind.unspecified:
     return None

jax/experimental/jax2tf/jax2tf.py

@@ -38,7 +38,8 @@ from jax import tree_util
 from jax import sharding
 from jax.experimental import maps
 from jax.experimental.export import shape_poly
-from jax.experimental.export import export
+from jax.experimental.export import _export
+from jax.experimental import export
 from jax.experimental.jax2tf import impl_no_xla
 from jax.interpreters import xla
 
@@ -515,7 +516,7 @@ class NativeSerializationImpl(SerializationImpl):
 
   def get_vjp_fun(self) -> tuple[Callable,
                                  Sequence[core.AbstractValue]]:
-    return export._get_vjp_fun(self.fun_jax,
+    return _export._get_vjp_fun(self.fun_jax,
                                 in_tree=self.exported.in_tree,
                                 in_avals=self.exported.in_avals,
                                 in_shardings=self.exported.in_shardings,
@@ -587,7 +588,7 @@ class GraphSerializationImpl(SerializationImpl):
     # We reuse the code for native serialization to get the VJP functions,
     # except we use unspecified shardings, and we do not apply a jit on the
     # VJP. This matches the older behavior of jax2tf for graph serialization.
-    return export._get_vjp_fun(self.fun_jax,
+    return _export._get_vjp_fun(self.fun_jax,
                                 in_tree=self.in_tree,
                                 in_avals=self.args_avals_flat,
                                 in_shardings=(None,) * len(self.args_avals_flat),

jax/experimental/jax2tf/tests/call_tf_test.py

@@ -29,7 +29,7 @@ from jax._src import test_util as jtu
 from jax._src.lib.mlir import ir
 from jax._src.lib.mlir.dialects import hlo
 from jax.experimental import jax2tf
-from jax.experimental.export import export
+from jax.experimental import export
 from jax.experimental.jax2tf.tests import tf_test_util
 import numpy as np
 

jax/experimental/jax2tf/tests/jax2tf_test.py

@@ -37,9 +37,8 @@ from jax._src import core
 from jax._src import source_info_util
 from jax._src import test_util as jtu
 from jax._src import xla_bridge as xb
-from jax._src.interpreters import mlir
 from jax.experimental import jax2tf
-from jax.experimental.export import export
+from jax.experimental import export
 from jax.experimental.jax2tf.tests import tf_test_util
 from jax.experimental.maps import xmap
 from jax.experimental.shard_map import shard_map

jax/experimental/jax2tf/tests/tf_test_util.py

@@ -31,7 +31,7 @@ from jax._src import test_util as jtu
 from jax import tree_util
 
 from jax.experimental import jax2tf
-from jax.experimental.export import export
+from jax.experimental import export
 from jax._src import config
 from jax._src import xla_bridge
 import numpy as np

tests/export_back_compat_test.py

@@ -27,7 +27,8 @@ import numpy as np
 
 import jax
 from jax import lax
-from jax.experimental.export import export
+from jax.experimental import export
+from jax.experimental.export import _export
 from jax._src.internal_test_util import export_back_compat_test_util as bctu
 
 from jax._src.internal_test_util.export_back_compat_test_data import cpu_ducc_fft
@@ -97,7 +98,7 @@ class CompatTest(bctu.CompatTestBase):
 
   def test_custom_call_coverage(self):
     """Tests that the back compat tests cover all the targets declared stable."""
-    targets_to_cover = set(export._CUSTOM_CALL_TARGETS_GUARANTEED_STABLE)
+    targets_to_cover = set(_export._CUSTOM_CALL_TARGETS_GUARANTEED_STABLE)
     # Add here all the testdatas that should cover the targets guaranteed
     # stable
     covering_testdatas = [

tests/export_harnesses_multi_platform_test.py

@@ -33,7 +33,7 @@ import numpy as np
 import jax
 from jax import lax
 from jax._src import test_util as jtu
-from jax.experimental.export import export
+from jax.experimental import export
 from jax._src.internal_test_util import test_harnesses
 
 

tests/export_test.py

@@ -26,10 +26,10 @@ import jax
 from jax import lax
 from jax import numpy as jnp
 from jax import tree_util
-from jax.experimental.export import export
-from jax.experimental.export import serialization
-from jax.experimental.shard_map import shard_map
+from jax.experimental import export
+from jax.experimental.export import _export
 from jax.experimental import pjit
+from jax.experimental.shard_map import shard_map
 from jax.sharding import NamedSharding
 from jax.sharding import Mesh
 from jax.sharding import PartitionSpec as P
@@ -146,8 +146,8 @@ def get_exported(fun, vjp_order=0,
   """Like export.export but with serialization + deserialization."""
   def serde_exported(*fun_args, **fun_kwargs):
     exp = export.export(fun, **export_kwargs)(*fun_args, **fun_kwargs)
-    serialized = serialization.serialize(exp, vjp_order=vjp_order)
-    return serialization.deserialize(serialized)
+    serialized = export.serialize(exp, vjp_order=vjp_order)
+    return export.deserialize(serialized)
   return serde_exported
 
 class JaxExportTest(jtu.JaxTestCase):
@@ -1139,7 +1139,7 @@ class JaxExportTest(jtu.JaxTestCase):
       )
 
     exp = get_exported(f_jax)(x)
-    if exp.mlir_module_serialization_version >= export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version >= _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       self.assertEqual(["ForTestingOrderedEffect1()", "ForTestingOrderedEffect2()"],
                        sorted(str(e) for e in exp.ordered_effects))
       self.assertEqual(["ForTestingUnorderedEffect1()"],
@@ -1169,11 +1169,11 @@ class JaxExportTest(jtu.JaxTestCase):
       # Results
       r"!stablehlo.token .*jax.token = true.*"
       r"!stablehlo.token .*jax.token = true.*")
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       wrapped_main_expected_re = wrapped_main_expected_re.replace("!stablehlo.token", "tensor<0xi1>")
     self.assertRegex(mlir_module_str, wrapped_main_expected_re)
 
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       # The main function does not have tokens
       self.assertNotRegex(mlir_module_str, r"@main.*token")
     else:
@@ -1191,7 +1191,7 @@ class JaxExportTest(jtu.JaxTestCase):
         export.call_exported(exp)(x))
 
     lowered_outer = jax.jit(f_outer).lower(x)
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       self.assertEqual(["ForTestingOrderedEffect2()"],
                        [str(e) for e in lowered_outer._lowering.compile_args["ordered_effects"]])
     else:
@@ -1201,7 +1201,7 @@ class JaxExportTest(jtu.JaxTestCase):
                      sorted([str(e) for e in lowered_outer._lowering.compile_args["unordered_effects"]]))
 
     mlir_outer_module_str = str(lowered_outer.compiler_ir())
-    if exp.mlir_module_serialization_version >= export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version >= _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       main_expected_re = main_expected_re.replace("!stablehlo.token", "tensor<0xi1>")
       self.assertRegex(mlir_outer_module_str, main_expected_re)
 
@@ -1229,11 +1229,11 @@ class JaxExportTest(jtu.JaxTestCase):
       r"%arg3: tensor<\?x\?xf32>.*\) -> \("
       # Results
       r"!stablehlo.token {jax.token = true}, tensor<\?x\?xf32>.*\)")
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       wrapped_main_expected_re = wrapped_main_expected_re.replace("!stablehlo.token", "tensor<0xi1>")
     self.assertRegex(mlir_module_str, wrapped_main_expected_re)
 
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       # The main function does not have tokens
       self.assertNotRegex(mlir_module_str, r"@main.*token")
     else:
@@ -1276,11 +1276,11 @@ class JaxExportTest(jtu.JaxTestCase):
       r"%arg4: tensor<\?x\?xf32>.*\) -> \("
       # Results
       r"!stablehlo.token {jax.token = true}, tensor<\?x\?xf32>.*\)")
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       wrapped_main_expected_re = wrapped_main_expected_re.replace("!stablehlo.token", "tensor<0xi1>")
     self.assertRegex(mlir_module_str, wrapped_main_expected_re)
 
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       # The main function does not have tokens
       self.assertNotRegex(mlir_module_str, r"@main.*token")
     else:
@@ -1313,7 +1313,7 @@ class JaxExportTest(jtu.JaxTestCase):
     f_jax = jax.jit(f_jax, donate_argnums=(0,))
     exp = export.export(f_jax)(x)
     mlir_module_str = str(exp.mlir_module())
-    if exp.mlir_module_serialization_version < export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
+    if exp.mlir_module_serialization_version < _export._VERSION_START_SUPPORT_EFFECTS_WITH_REAL_TOKENS:
       self.assertRegex(mlir_module_str, r"@main.*tf.aliasing_output = 0")
       self.assertRegex(mlir_module_str, r"@_wrapped_jax_export_main.*tf.aliasing_output = 1")
     else:

tests/shape_poly_test.py

@@ -33,7 +33,7 @@ import operator as op
 import re
 
 import jax
-from jax.experimental.export import export
+from jax.experimental import export
 from jax.experimental.export import shape_poly
 from jax.experimental import pjit
 from jax import lax