Some cleanup

Author: ilevkivskyi

mypy/build.py

@@ -2822,6 +2822,7 @@ def fix_cross_refs(self) -> None:
         assert fixer_state.node_fixer is not None
         fixer_state.node_fixer.visit_symbol_table(self.tree.names)
         type_fixer = fixer_state.node_fixer.type_fixer
+        # Eagerly fix shared instances, before they are used by named_type() calls.
         if instance_cache.str_type is not None:
             instance_cache.str_type.accept(type_fixer)
         if instance_cache.function_type is not None:

mypy/fixup.py

@@ -55,7 +55,7 @@ def __init__(self, modules: dict[str, MypyFile], allow_missing: bool) -> None:
         # incremental cache load (since there may be cross-refs into deleted
         # modules)
         self.allow_missing = allow_missing
-        self.type_fixer = TypeFixer(modules, allow_missing)
+        self.type_fixer = TypeFixer(self.modules, allow_missing)
 
     # NOTE: This method isn't (yet) part of the NodeVisitor API.
     def visit_type_info(self, info: TypeInfo) -> None:
@@ -123,17 +123,17 @@ def visit_symbol_table(self, symtab: SymbolTable) -> None:
                     value.cross_ref = None
                     value.unfixed = False
                     value._node = self.modules[cross_ref]
+                # TODO: this should not be needed, looks like a daemon bug.
                 elif self.allow_missing:
-                    # TODO: this should not be needed, looks like a daemon bug.
                     self.resolve_cross_ref(value)
             # Look at private attribute to avoid triggering fixup eagerly.
             elif isinstance(value._node, TypeInfo):
-                # TypeInfo has no accept().
                 self.visit_type_info(value._node)
             else:
                 value.stored_info = self.current_info
 
     def resolve_cross_ref(self, value: SymbolTableNode) -> None:
+        """Replace cross-reference with an actual referred node."""
         assert value.cross_ref is not None
         cross_ref = value.cross_ref
         value.cross_ref = None

mypy/nodes.py

@@ -4731,9 +4731,10 @@ class SymbolTableNode:
     they should be correct.
 
     Attributes:
-        node: AST node of definition. Among others, this can be one of
+        _node: AST node of definition. Among others, this can be one of
             FuncDef, Var, TypeInfo, TypeVarExpr or MypyFile -- or None
-            for cross_ref that hasn't been fixed up yet.
+            for cross_ref that hasn't been fixed up yet. Should not be accessed
+            directly, only via the `node` property.
         kind: Kind of node. Possible values:
                - LDEF: local definition
                - GDEF: global (module-level) definition
@@ -4743,25 +4744,20 @@ class SymbolTableNode:
         module_public: If False, this name won't be imported via
             'from <module> import *'. This has no effect on names within
             classes.
-        module_hidden: If True, the name will be never exported (needed for
+        module_hidden: If True, the name will never be exported (needed for
             stub files)
         cross_ref: For deserialized MypyFile nodes, the referenced module
             name; for other nodes, optionally the name of the referenced object.
         implicit: Was this defined by assignment to self attribute?
         plugin_generated: Was this symbol generated by a plugin?
             (And therefore needs to be removed in aststrip.)
-        no_serialize: Do not serialize this node if True. This is used to prevent
-            keys in the cache that refer to modules on which this file does not
-            depend. Currently this can happen if there is a module not in build
-            used e.g. like this:
-                import a.b.c # type: ignore
-            This will add a submodule symbol to parent module `a` symbol table,
-            but `a.b` is _not_ added as its dependency. Therefore, we should
-            not serialize these symbols as they may not be found during fixup
-            phase, instead they will be re-added during subsequent patch parents
-            phase.
-            TODO: Refactor build.py to make dependency tracking more transparent
-            and/or refactor look-up functions to not require parent patching.
+        no_serialize: Do not serialize this node if True. This is used for internal
+            and/or temporary symbols such as function redefinitions.
+        unfixed: Indicates that this symbol is fresh after deserialization and
+            needs fixup, such as resolving cross-references etc.
+        stored_info: TypeInfo containing this symbol. Normally code accesses this
+            on the `node` attribute, but it may be not ready during deserialization,
+            so we temporarily store info on the symbol itself.
 
     NOTE: No other attributes should be added to this class unless they
     are shared by all node kinds.
@@ -4831,6 +4827,7 @@ def node(self) -> SymbolNode | None:
                 assert node is not None
                 if self.stored_info is not None:
                     set_info(node, self.stored_info)
+                    self.stored_info = None
                 node.accept(node_fixer)
                 self.unfixed = False
         return self._node
@@ -5276,6 +5273,7 @@ def local_definitions(
 
 
 def set_info(node: SymbolNode, info: TypeInfo) -> None:
+    """Add `info` attribute to all relevant components of the node."""
     if isinstance(node, (FuncDef, Var)):
         node.info = info
     elif isinstance(node, Decorator):

mypy/options.py

@@ -299,7 +299,7 @@ def __init__(self) -> None:
         # Caching and incremental checking options
         self.incremental = True
         self.cache_dir = defaults.CACHE_DIR
-        self.sqlite_cache = False
+        self.sqlite_cache = True
         self.fixed_format_cache = True
         self.debug_cache = False
         self.skip_version_check = False

mypy/plugins/common.py

@@ -433,6 +433,7 @@ def add_attribute_to_class(
     return node
 
 
+# We keep the unused `api` parameter, to avoid breaking 3rd party dataclass-like plugins.
 def deserialize_and_fixup_type(data: str | JsonDict, api: SemanticAnalyzerPluginInterface) -> Type:
     typ = deserialize_type(data)
     assert fixer_state.node_fixer is not None

mypy/semanal.py

@@ -7148,7 +7148,7 @@ def add_redefinition(self, names: SymbolTable, name: str, symbol: SymbolTableNod
         i = 1
         # Don't serialize redefined nodes. They are likely to have
         # busted internal references which can cause problems with
-        # serialization and they can't have any external references to
+        # serialization, and they can't have any external references to
         # them.
         symbol.no_serialize = True
         while True: