Move block_overlapping_deps to _compat.py. (#4904)

In anticipation of the growing number of device deprecations, going to add this "officially" to `_compat.py`.

cirq-core/cirq/_compat.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 """Workarounds for compatibility issues between versions and libraries."""
+import contextlib
 import dataclasses
 import functools
 import importlib
@@ -649,3 +650,23 @@ def __getattr__(self, name):
             return getattr(parent_module, name)
 
     sys.modules[old_parent] = Wrapped(parent_module.__name__, parent_module.__doc__)
+
+
+@contextlib.contextmanager
+def block_overlapping_deprecation(match_regex: str):
+    """Context to block deprecation warnings raised within it.
+
+    Useful if a function call might raise more than one warning,
+    where only one warning is desired.
+
+    Args:
+        match_regex: DeprecationWarnings with message fields matching
+            match_regex will be blocked.
+    """
+    with warnings.catch_warnings():
+        warnings.filterwarnings(
+            action='ignore',
+            category=DeprecationWarning,
+            message=f'(.|\n)*{match_regex}(.|\n)*',
+        )
+        yield

cirq-core/cirq/_compat_test.py

@@ -34,6 +34,7 @@
 
 import cirq.testing
 from cirq._compat import (
+    block_overlapping_deprecation,
     proper_repr,
     dataclass_repr,
     deprecated,
@@ -887,3 +888,17 @@ def _dir_is_still_valid_inner():
 
     for m in ['fake_a', 'info', 'module_a', 'sys']:
         assert m in dir(mod)
+
+
+def test_block_overlapping_deprecation():
+    @deprecated(fix="Don't use g.", deadline="v1000.0")
+    def g(y):
+        return y - 4
+
+    @deprecated(fix="Don't use f.", deadline="v1000.0")
+    def f(x):
+        with block_overlapping_deprecation('g'):
+            return [g(i + 1) for i in range(x)]
+
+    with cirq.testing.assert_deprecated('f', deadline='v1000.0', count=1):
+        f(5)

cirq-core/cirq/circuits/circuit.py

@@ -20,13 +20,11 @@
 """
 
 import abc
-import contextlib
 import enum
 import html
 import itertools
 import math
 import re
-import warnings
 from collections import defaultdict
 from typing import (
     AbstractSet,
@@ -73,17 +71,6 @@
 _DEVICE_DEP_MESSAGE = 'Attaching devices to circuits will no longer be supported.'
 
 
-@contextlib.contextmanager
-def _block_overlapping_deprecation():
-    with warnings.catch_warnings():
-        warnings.filterwarnings(
-            action='ignore',
-            category=DeprecationWarning,
-            message=f'(.|\n)*{re.escape(_DEVICE_DEP_MESSAGE)}(.|\n)*',
-        )
-        yield
-
-
 class Alignment(enum.Enum):
     # Stop when left ends are lined up.
     LEFT = 1
@@ -1890,7 +1877,7 @@ def with_device(
         Returns:
             The translated circuit.
         """
-        with _block_overlapping_deprecation():
+        with _compat.block_overlapping_deprecation(re.escape(_DEVICE_DEP_MESSAGE)):
             return Circuit(
                 [
                     ops.Moment(
@@ -1958,7 +1945,7 @@ def transform_qubits(
         if new_device is None and self._device == devices.UNCONSTRAINED_DEVICE:
             return Circuit(op_list)
 
-        with _block_overlapping_deprecation():
+        with _compat.block_overlapping_deprecation(re.escape(_DEVICE_DEP_MESSAGE)):
             return Circuit(op_list, device=self._device if new_device is None else new_device)
 
     def _prev_moment_available(self, op: 'cirq.Operation', end_moment_index: int) -> Optional[int]:
@@ -2377,7 +2364,7 @@ def _resolve_parameters_(
             resolved_moments.append(new_moment)
         if self._device == devices.UNCONSTRAINED_DEVICE:
             return Circuit(resolved_moments)
-        with _block_overlapping_deprecation():
+        with _compat.block_overlapping_deprecation(re.escape(_DEVICE_DEP_MESSAGE)):
             return Circuit(resolved_moments, device=self._device)
 
     @property

cirq-core/cirq/circuits/circuit_dag.py

@@ -11,7 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import re
 from typing import Any, Callable, Dict, Generic, Iterator, TypeVar, cast, TYPE_CHECKING
 
 import functools
@@ -138,7 +138,7 @@ def from_ops(
         if device == devices.UNCONSTRAINED_DEVICE:
             dag = CircuitDag(can_reorder=can_reorder)
         else:
-            with circuit._block_overlapping_deprecation():
+            with _compat.block_overlapping_deprecation(re.escape(circuit._DEVICE_DEP_MESSAGE)):
                 dag = CircuitDag(can_reorder=can_reorder, device=device)
 
         for op in ops.flatten_op_tree(operations):

cirq-core/cirq/circuits/frozen_circuit.py

@@ -24,8 +24,6 @@
     Tuple,
     Union,
 )
-import contextlib
-import warnings
 import re
 
 from cirq.circuits import AbstractCircuit, Alignment, Circuit
@@ -44,17 +42,6 @@
 _DEVICE_DEP_MESSAGE = 'Attaching devices to circuits will no longer be supported.'
 
 
-@contextlib.contextmanager
-def _block_overlapping_deprecation():
-    with warnings.catch_warnings():
-        warnings.filterwarnings(
-            action='ignore',
-            category=DeprecationWarning,
-            message=f'(.|\n)*{re.escape(_DEVICE_DEP_MESSAGE)}(.|\n)*',
-        )
-        yield
-
-
 class FrozenCircuit(AbstractCircuit, protocols.SerializableByKey):
     """An immutable version of the Circuit data structure.
 
@@ -91,7 +78,7 @@ def __init__(
         if device == devices.UNCONSTRAINED_DEVICE:
             base = Circuit(contents, strategy=strategy)
         else:
-            with _block_overlapping_deprecation():
+            with _compat.block_overlapping_deprecation(re.escape(_DEVICE_DEP_MESSAGE)):
                 base = Circuit(contents, strategy=strategy, device=device)
 
         self._moments = tuple(base.moments)
@@ -225,7 +212,7 @@ def with_device(
         new_device: 'cirq.Device',
         qubit_mapping: Callable[['cirq.Qid'], 'cirq.Qid'] = lambda e: e,
     ) -> 'FrozenCircuit':
-        with _block_overlapping_deprecation():
+        with _compat.block_overlapping_deprecation(re.escape(_DEVICE_DEP_MESSAGE)):
             return self.unfreeze().with_device(new_device, qubit_mapping).freeze()
 
     def _resolve_parameters_(