Add rules for deprecated AMP APIs (#87)

Add codemods for `torch.cuda.amp.autocast` and `torch.cpu.amp.autocast`,
and checkers for `torch.cuda.amp.custom_fwd` and
`torch.cuda.amp.custom_bwd`.

tests/fixtures/deprecated_symbols/checker/amp.py

@@ -0,0 +1,10 @@
+import torch
+
+torch.cuda.amp.autocast()
+torch.cuda.amp.custom_fwd()
+torch.cuda.amp.custom_bwd()
+
+dtype = torch.float32
+maybe_autocast = torch.cpu.amp.autocast()
+maybe_autocast = torch.cpu.amp.autocast(dtype=torch.bfloat16)
+maybe_autocast = torch.cpu.amp.autocast(dtype=dtype)

tests/fixtures/deprecated_symbols/checker/amp.txt

@@ -0,0 +1,6 @@
+3:1 TOR101 Use of deprecated function torch.cuda.amp.autocast
+4:1 TOR101 Use of deprecated function torch.cuda.amp.custom_fwd
+5:1 TOR101 Use of deprecated function torch.cuda.amp.custom_bwd
+8:18 TOR101 Use of deprecated function torch.cpu.amp.autocast
+9:18 TOR101 Use of deprecated function torch.cpu.amp.autocast
+10:18 TOR101 Use of deprecated function torch.cpu.amp.autocast

tests/fixtures/deprecated_symbols/codemod/amp.in.py

@@ -0,0 +1,11 @@
+import torch
+
+dtype = torch.float32
+
+maybe_autocast = torch.cuda.amp.autocast()
+maybe_autocast = torch.cuda.amp.autocast(dtype=torch.bfloat16)
+maybe_autocast = torch.cuda.amp.autocast(dtype=dtype)
+
+maybe_autocast = torch.cpu.amp.autocast()
+maybe_autocast = torch.cpu.amp.autocast(dtype=torch.bfloat16)
+maybe_autocast = torch.cpu.amp.autocast(dtype=dtype)

tests/fixtures/deprecated_symbols/codemod/amp.out.py

@@ -0,0 +1,11 @@
+import torch
+
+dtype = torch.float32
+
+maybe_autocast = torch.amp.autocast("cuda")
+maybe_autocast = torch.amp.autocast("cuda", dtype=torch.bfloat16)
+maybe_autocast = torch.amp.autocast("cuda", dtype=dtype)
+
+maybe_autocast = torch.amp.autocast("cpu")
+maybe_autocast = torch.amp.autocast("cpu", dtype=torch.bfloat16)
+maybe_autocast = torch.amp.autocast("cpu", dtype=dtype)

torchfix/deprecated_symbols.yaml

@@ -83,6 +83,22 @@
   remove_pr:
   reference: https://github.com/pytorch-labs/torchfix#torchbackendscudasdp_kernel
 
+- name: torch.cuda.amp.autocast
+  deprecate_pr: TBA
+  remove_pr:
+
+- name: torch.cuda.amp.custom_fwd
+  deprecate_pr: TBA
+  remove_pr:
+
+- name: torch.cuda.amp.custom_bwd
+  deprecate_pr: TBA
+  remove_pr:
+
+- name: torch.cpu.amp.autocast
+  deprecate_pr: TBA
+  remove_pr:
+
 # functorch
 - name: functorch.vmap
   deprecate_pr: TBA

torchfix/visitors/deprecated_symbols/__init__.py

@@ -1,20 +1,23 @@
-import libcst as cst
 import pkgutil
+from typing import List, Optional
+
+import libcst as cst
 import yaml
-from typing import Optional, List
 
 from ...common import (
-    TorchVisitor,
-    TorchError,
     call_with_name_changes,
     check_old_names_in_import_from,
+    TorchError,
+    TorchVisitor,
 )
 
-from .range import call_replacement_range
-from .cholesky import call_replacement_cholesky
+from .amp import call_replacement_cpu_amp_autocast, call_replacement_cuda_amp_autocast
 from .chain_matmul import call_replacement_chain_matmul
+from .cholesky import call_replacement_cholesky
 from .qr import call_replacement_qr
 
+from .range import call_replacement_range
+
 
 class TorchDeprecatedSymbolsVisitor(TorchVisitor):
     ERRORS: List[TorchError] = [
@@ -49,6 +52,8 @@ def _call_replacement(
             "torch.range": call_replacement_range,
             "torch.chain_matmul": call_replacement_chain_matmul,
             "torch.qr": call_replacement_qr,
+            "torch.cuda.amp.autocast": call_replacement_cuda_amp_autocast,
+            "torch.cpu.amp.autocast": call_replacement_cpu_amp_autocast,
         }
         replacement = None
 

torchfix/visitors/deprecated_symbols/amp.py

@@ -0,0 +1,26 @@
+import libcst as cst
+
+from ...common import get_module_name
+
+
+def call_replacement_cpu_amp_autocast(node: cst.Call) -> cst.CSTNode:
+    return _call_replacement_amp(node, "cpu")
+
+
+def call_replacement_cuda_amp_autocast(node: cst.Call) -> cst.CSTNode:
+    return _call_replacement_amp(node, "cuda")
+
+
+def _call_replacement_amp(node: cst.Call, device: str) -> cst.CSTNode:
+    """
+    Replace `torch.cuda.amp.autocast()` with `torch.amp.autocast("cuda")` and
+    Replace `torch.cpu.amp.autocast()` with `torch.amp.autocast("cpu")`.
+    """
+    device_arg = cst.ensure_type(cst.parse_expression(f'f("{device}")'), cst.Call).args[
+        0
+    ]
+
+    module_name = get_module_name(node, "torch")
+    replacement = cst.parse_expression(f"{module_name}.amp.autocast(args)")
+    replacement = replacement.with_changes(args=(device_arg, *node.args))
+    return replacement