Fix daemon crashes related to ParamSpec and TypeVarTuple (#13381)

* Fix daemon crashes related to ParamSpec and TypeVarTuple

Fix daemon crash when using fine-grained caching and ParamSpec, with
traceback like this (when using a compiled mypy):

```
Traceback (most recent call last):
  File "mypy/dmypy_server.py", line 230, in serve
  File "mypy/dmypy_server.py", line 273, in run_command
  File "mypy/dmypy_server.py", line 372, in cmd_recheck
  File "mypy/dmypy_server.py", line 529, in fine_grained_increment
  File "mypy/server/update.py", line 245, in update
  File "mypy/server/update.py", line 328, in update_one
  File "mypy/server/update.py", line 387, in update_module
  File "mypy/server/astdiff.py", line 158, in snapshot_symbol_table
  File "mypy/server/astdiff.py", line 236, in snapshot_type
  File "mypy/types.py", line 1173, in accept
  File "mypy/server/astdiff.py", line 300, in visit_instance
  File "mypy/nodes.py", line 2764, in fullname
AttributeError: attribute 'TypeInfo' of '_fullname' undefined
```

Also fix TypeVarTuple crashes when using daemon.

Co-authored-by: Ivan Levkivskyi <levkivskyi@gmail.com>

Author: 2 people

mypy/fixup.py

@@ -13,10 +13,12 @@
     FuncDef,
     MypyFile,
     OverloadedFuncDef,
+    ParamSpecExpr,
     SymbolTable,
     TypeAlias,
     TypeInfo,
     TypeVarExpr,
+    TypeVarTupleExpr,
     Var,
 )
 from mypy.types import (
@@ -164,6 +166,12 @@ def visit_type_var_expr(self, tv: TypeVarExpr) -> None:
             value.accept(self.type_fixer)
         tv.upper_bound.accept(self.type_fixer)
 
+    def visit_paramspec_expr(self, p: ParamSpecExpr) -> None:
+        p.upper_bound.accept(self.type_fixer)
+
+    def visit_type_var_tuple_expr(self, tv: TypeVarTupleExpr) -> None:
+        tv.upper_bound.accept(self.type_fixer)
+
     def visit_var(self, v: Var) -> None:
         if self.current_info is not None:
             v.info = self.current_info

mypy/server/astdiff.py

@@ -68,6 +68,7 @@ class level -- these are handled at attribute level (say, 'mod.Cls.method'
     TypeAlias,
     TypeInfo,
     TypeVarExpr,
+    TypeVarTupleExpr,
     Var,
 )
 from mypy.types import (
@@ -189,6 +190,8 @@ def snapshot_symbol_table(name_prefix: str, table: SymbolTable) -> dict[str, Sna
             )
         elif isinstance(node, ParamSpecExpr):
             result[name] = ("ParamSpec", node.variance, snapshot_type(node.upper_bound))
+        elif isinstance(node, TypeVarTupleExpr):
+            result[name] = ("TypeVarTuple", node.variance, snapshot_type(node.upper_bound))
         else:
             assert symbol.kind != UNBOUND_IMPORTED
             if node and get_prefix(node.fullname) != name_prefix:

mypy/test/testfinegrained.py

@@ -151,6 +151,7 @@ def get_options(self, source: str, testcase: DataDrivenTestCase, build_cache: bo
         options.use_fine_grained_cache = self.use_cache and not build_cache
         options.cache_fine_grained = self.use_cache
         options.local_partial_types = True
+        options.enable_incomplete_features = True
         if re.search("flags:.*--follow-imports", source) is None:
             # Override the default for follow_imports
             options.follow_imports = "error"

test-data/unit/fine-grained.test

@@ -9819,6 +9819,89 @@ x: str
 [out]
 ==
 
+[case testParamSpecCached]
+import a
+
+[file a.py]
+import b
+
+def f(x: int) -> str: return 'x'
+
+b.foo(f)
+
+[file a.py.2]
+import b
+
+def f(x: int) -> str: return 'x'
+
+reveal_type(b.foo(f))
+
+[file b.py]
+from typing import TypeVar, Callable, Union
+from typing_extensions import ParamSpec
+
+P = ParamSpec("P")
+T = TypeVar("T")
+
+def foo(f: Callable[P, T]) -> Callable[P, Union[T, None]]:
+    return f
+
+[file b.py.2]
+from typing import TypeVar, Callable, Union
+from typing_extensions import ParamSpec
+
+P = ParamSpec("P")
+T = TypeVar("T")
+
+def foo(f: Callable[P, T]) -> Callable[P, Union[T, None]]:
+    return f
+
+x = 0  # Arbitrary change to trigger reprocessing
+
+[builtins fixtures/dict.pyi]
+[out]
+==
+a.py:5: note: Revealed type is "def (x: builtins.int) -> builtins.str"
+
+[case testTypeVarTupleCached]
+import a
+
+[file a.py]
+import b
+
+def f(x: int) -> str: return 'x'
+
+b.foo((1, 'x'))
+
+[file a.py.2]
+import b
+
+reveal_type(b.foo((1, 'x')))
+
+[file b.py]
+from typing import Tuple
+from typing_extensions import TypeVarTuple, Unpack
+
+Ts = TypeVarTuple("Ts")
+
+def foo(t: Tuple[Unpack[Ts]]) -> Tuple[Unpack[Ts]]:
+    return t
+
+[file b.py.2]
+from typing import Tuple
+from typing_extensions import TypeVarTuple, Unpack
+
+Ts = TypeVarTuple("Ts")
+
+def foo(t: Tuple[Unpack[Ts]]) -> Tuple[Unpack[Ts]]:
+    return t
+
+x = 0  # Arbitrary change to trigger reprocessing
+[builtins fixtures/dict.pyi]
+[out]
+==
+a.py:3: note: Revealed type is "Tuple[Literal[1]?, Literal['x']?]"
+
 [case testUnpackKwargsUpdateFine]
 # flags: --enable-incomplete-features
 import m