Remove export_map logic (#20490)

Follow up to #20487

Author: hauntsaninja

mypy/semanal.py

@@ -493,10 +493,6 @@ def __init__(
         # since it's possible that the name will be there once the namespace is complete.
         self.incomplete_namespaces = incomplete_namespaces
         self.all_exports: list[str] = []
-        # Map from module id to list of explicitly exported names (i.e. names in __all__).
-        # This is used by stubgen/stubtest, DO NOT use for any other purposes as it is
-        # not populated on incremental runs (nor in parallel mode).
-        self.export_map: dict[str, list[str]] = {}
         self.plugin = plugin
         # If True, process function definitions. If False, don't. This is used
         # for processing module top levels in fine-grained incremental mode.
@@ -724,7 +720,6 @@ def refresh_top_level(self, file_node: MypyFile) -> None:
         if file_node.fullname == "typing_extensions":
             self.add_typing_extension_aliases(file_node)
         self.adjust_public_exports()
-        self.export_map[self.cur_mod_id] = self.all_exports
         self.all_exports = []
 
     def add_implicit_module_attrs(self, file_node: MypyFile) -> None:

mypy/stubgen.py

@@ -1773,7 +1773,9 @@ def generate_asts_for_modules(
         mod.ast = res.graph[mod.module].tree
         # Use statically inferred __all__ if there is no runtime one.
         if mod.runtime_all is None:
-            mod.runtime_all = res.manager.semantic_analyzer.export_map[mod.module]
+            mod_names = res.manager.semantic_analyzer.modules[mod.module].names
+            if "__all__" in mod_names:
+                mod.runtime_all = [name for name, sym in mod_names.items() if sym.module_public]
 
 
 def generate_stub_for_py_module(