[precompile] Detect source code changes for save/load. (#156432)

Go through all dynamo traced functions and compute checksum for them. While loading a precompilation back to memory, we will always check the checksum and refuse to load when
source code changes are detected.

Differential Revision: [D76987123](https://our.internmc.facebook.com/intern/diff/D76987123/)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/156432
Approved by: https://github.com/jansel, https://github.com/jamesjwu

test/dynamo/test_package.py

@@ -1,6 +1,9 @@
 # Owner(s): ["module: dynamo"]
 
+import importlib
 import os
+import sys
+import tempfile
 import unittest
 
 import torch
@@ -185,6 +188,76 @@ class TestPackage(torch._inductor.test_case.TestCase):
             ):
                 compiled_fn(*args2)
 
+    def test_file_change(self):
+        ctx = DiskDynamoStore()
+
+        def import_from_path(module_name, file_path):
+            spec = importlib.util.spec_from_file_location(module_name, file_path)
+            module = importlib.util.module_from_spec(spec)
+            sys.modules[module_name] = module
+            spec.loader.exec_module(module)
+            return module
+
+        mock_module_add_original = """
+def add(x, y):
+    return x + y
+"""
+
+        mock_module_add_modified = """
+def add(x, y):
+    return x - y
+"""
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            mock_module_add_original_path = os.path.join(
+                tmp_dir, "mock_module_add_original.py"
+            )
+            mock_module_add_modified_path = os.path.join(
+                tmp_dir, "mock_module_add_modified.py"
+            )
+            with open(mock_module_add_original_path, "w") as f:
+                f.write(mock_module_add_original)
+            with open(mock_module_add_modified_path, "w") as f:
+                f.write(mock_module_add_modified)
+
+            module = import_from_path(
+                "torch.test_package_helper",
+                mock_module_add_original_path,
+            )
+
+            def fn(x):
+                return module.add(x, 1)
+
+            args = (torch.randn(3, 2),)
+
+            def guard_filter_fn(guards):
+                return [
+                    guard.guard_type not in ("CLOSURE_MATCH", "FUNCTION_MATCH")
+                    for guard in guards
+                ]
+
+            # Saving
+            package = CompilePackage(fn)
+            compiled_fn = torch._dynamo.optimize(
+                backend="eager", package=package, guard_filter_fn=guard_filter_fn
+            )(fn)
+            compiled_fn(*args)
+            for backend_id, backend in package.cached_backends.items():
+                ctx.record_eager_backend(backend_id, backend)
+            ctx.save_package(package, self.path())
+
+            module = import_from_path(
+                "torch.test_package_helper",
+                mock_module_add_modified_path,
+            )
+            with self.assertRaisesRegex(RuntimeError, "Source code changes detected"):
+                ctx.load_package(fn, self.path())
+
+            module = import_from_path(
+                "torch.test_package_helper",
+                mock_module_add_original_path,
+            )
+            ctx.load_package(fn, self.path())
+
 
 if __name__ == "__main__":
     from torch._dynamo.test_case import run_tests

torch/_dynamo/convert_frame.py

@@ -976,6 +976,7 @@ def _compile(
         if package is not None:
             assert check_fn.guards_state is not None
             package.add_guarded_code(check_fn.guards_state, out_code)
+            package.add_inlined_source(output.tracing_context.traced_code)
 
         compile_id_str = str(compile_id) if compile_id is not None else "Unknown"
         annotation_str = "Torch-Compiled Region: " + compile_id_str

torch/_dynamo/package.py

@@ -14,6 +14,7 @@ import dataclasses
 import functools
 import hashlib
 import importlib
+import inspect
 import logging
 import os
 import pickle
@@ -96,6 +97,14 @@ _BackendId = NewType("_BackendId", str)  # __compiled_fn
 _FunctionId = NewType("_FunctionId", str)  # __resume_at
 
 
+@dataclasses.dataclass(frozen=True)
+class InlinedSource:
+    module: str
+    firstlineno: int
+    lastlineno: int
+    checksum: str
+
+
 @dataclasses.dataclass
 class _DynamoCodeCacheEntry:
     """
@@ -124,6 +133,7 @@ class _DynamoCodeCacheEntry:
 @dataclasses.dataclass
 class _DynamoCacheEntry:
     codes: list[_DynamoCodeCacheEntry]
+    inlined_sources: set[InlinedSource]
     python_version: str = platform.python_version()
     torch_version: str = torch.__version__
 
@@ -142,6 +152,22 @@ class _DynamoCacheArtifact(PrecompileCacheArtifact[_DynamoCacheEntry]):
         return pickle.loads(self.content)
 
 
+def _hash_source(source: str) -> str:
+    sha256_hash = hashlib.sha256()
+    sha256_hash.update(source.encode())
+    return sha256_hash.hexdigest()
+
+
+def _get_sourcelines(
+    m: types.ModuleType, firstlineno: int, lastlineno: int
+) -> list[str]:
+    return inspect.getsourcelines(m)[0][firstlineno - 1 : lastlineno - 1]
+
+
+def _hash_sourcelines(m: types.ModuleType, firstlineno: int, lastlineno: int) -> str:
+    return _hash_source("".join(_get_sourcelines(m, firstlineno, lastlineno)))
+
+
 class CompilePackage:
     """
     CompilePackage is considered a low level component and should not be directly exposed to
@@ -155,7 +181,12 @@ class CompilePackage:
         updates with compiled functions and resume functions.
     """
 
-    def __init__(self, fn: Any, dynamo: Optional[_DynamoCacheEntry] = None) -> None:
+    def __init__(
+        self,
+        fn: Any,
+        dynamo: Optional[_DynamoCacheEntry] = None,
+        ignore_inlined_sources: bool = False,
+    ) -> None:
         self._innermost_fn = None
         self._codes: dict[types.CodeType, _DynamoCodeCacheEntry] = {}
 
@@ -164,14 +195,22 @@ class CompilePackage:
 
         # For debugging/testing purpose only.
         self._cached_backends: dict[_BackendId, Any] = {}
+        self._inlined_sources: set[InlinedSource] = set()
+        self._resume_codes: set[types.CodeType] = set()
 
-        self._initialize(fn, dynamo)
+        self._initialize(fn, dynamo, ignore_inlined_sources)
         self.uninstall()
         self.validate()
 
-    def _initialize(self, fn: Any, dynamo: Optional[_DynamoCacheEntry] = None) -> None:
+    def _initialize(
+        self,
+        fn: Any,
+        dynamo: Optional[_DynamoCacheEntry] = None,
+        ignore_inlined_sources: bool = False,
+    ) -> None:
         from .eval_frame import innermost_fn
 
+        self._inlined_sources = set()
         self._innermost_fn = innermost_fn(fn)
         assert self._innermost_fn is not None
         if dynamo is not None:
@@ -184,6 +223,16 @@ class CompilePackage:
                 raise RuntimeError(
                     f"Compile package was created with a different PyTorch version: {dynamo.torch_version}"
                 )
+            if not ignore_inlined_sources:
+                for code in dynamo.inlined_sources:
+                    m = importlib.import_module(code.module)
+                    checksum = _hash_sourcelines(m, code.firstlineno, code.lastlineno)
+                    if checksum != code.checksum:
+                        raise RuntimeError(
+                            f"Source code changes detected for {code.module} (line {code.firstlineno} - line {code.lastlineno})"
+                        )
+
+                self._inlined_sources = dynamo.inlined_sources
 
             main, *codes = dynamo.codes
             self._codes = {self._innermost_fn.__code__: main}
@@ -252,6 +301,27 @@ class CompilePackage:
         )
         self._current_entry.guarded_codes.append(guarded_code_entry)
 
+    def add_inlined_source(self, sources: list[types.CodeType]) -> None:
+        for code in sources:
+            if code in self._resume_codes:
+                continue
+            module = inspect.getmodule(code)
+            if module is None:
+                continue
+            source = inspect.getsource(code)
+            lastlineno = code.co_firstlineno + len(inspect.getsourcelines(code)[0])
+            assert source == "".join(
+                _get_sourcelines(module, code.co_firstlineno, lastlineno)
+            )
+            self._inlined_sources.add(
+                InlinedSource(
+                    module=module.__name__,
+                    firstlineno=code.co_firstlineno,
+                    lastlineno=lastlineno,
+                    checksum=_hash_source(source),
+                )
+            )
+
     def add_resume_function(
         self,
         python_code: types.CodeType,
@@ -261,6 +331,7 @@ class CompilePackage:
         self._add_function(
             python_code, python_module, _FunctionId(name) if name else None
         )
+        self._resume_codes.add(python_code)
 
     def add_import_source(self, alias: str, module_name: str) -> None:
         assert self._current_entry is not None
@@ -345,7 +416,9 @@ class CompilePackage:
 
     def cache_entry(self) -> _DynamoCacheEntry:
         self.validate()
-        return _DynamoCacheEntry(codes=list(self._codes.values()))
+        return _DynamoCacheEntry(
+            codes=list(self._codes.values()), inlined_sources=self._inlined_sources
+        )
 
 
 @CacheArtifactFactory.register