Enable generation and caching of fine-grained dependencies from norma…

…l runs (python#4526)

mypy/build.py

@@ -52,6 +52,7 @@
 from mypy.version import __version__
 from mypy.plugin import Plugin, DefaultPlugin, ChainedPlugin
 from mypy.defaults import PYTHON3_VERSION_MIN
+from mypy.server.deps import get_dependencies
 
 
 PYTHON_EXTENSIONS = ['.pyi', '.py']
@@ -1183,6 +1184,7 @@ def compute_hash(text: str) -> str:
 
 
 def write_cache(id: str, path: str, tree: MypyFile,
+                serialized_fine_grained_deps: Dict[str, List[str]],
                 dependencies: List[str], suppressed: List[str],
                 child_modules: List[str], dep_prios: List[int],
                 old_interface_hash: str, source_hash: str,
@@ -1221,7 +1223,9 @@ def write_cache(id: str, path: str, tree: MypyFile,
     assert os.path.dirname(meta_json) == parent
 
     # Serialize data and analyze interface
-    data = tree.serialize()
+    data = {'tree': tree.serialize(),
+            'fine_grained_deps': serialized_fine_grained_deps,
+            }
     if manager.options.debug_cache:
         data_str = json.dumps(data, indent=2, sort_keys=True)
     else:
@@ -1523,6 +1527,8 @@ class State:
     # Whether the module has an error or any of its dependencies have one.
     transitive_error = False
 
+    fine_grained_deps = None  # type: Dict[str, Set[str]]
+
     # Type checker used for checking this file.  Use type_checker() for
     # access and to construct this on demand.
     _type_checker = None  # type: Optional[TypeChecker]
@@ -1551,6 +1557,7 @@ def __init__(self,
         self.id = id or '__main__'
         self.options = manager.options.clone_for_module(self.id)
         self._type_checker = None
+        self.fine_grained_deps = {}
         if not path and source is None:
             assert id is not None
             file_id = id
@@ -1734,7 +1741,9 @@ def load_tree(self) -> None:
         with open(self.meta.data_json) as f:
             data = json.load(f)
         # TODO: Assert data file wasn't changed.
-        self.tree = MypyFile.deserialize(data)
+        self.tree = MypyFile.deserialize(data['tree'])
+        self.fine_grained_deps = {k: set(v) for k, v in data['fine_grained_deps'].items()}
+
         self.manager.modules[self.id] = self.tree
         self.manager.add_stats(fresh_trees=1)
 
@@ -1977,6 +1986,19 @@ def _patch_indirect_dependencies(self,
             elif dep not in self.suppressed and dep in self.manager.missing_modules:
                 self.suppressed.append(dep)
 
+    def compute_fine_grained_deps(self) -> None:
+        assert self.tree is not None
+        if '/typeshed/' in self.xpath or self.xpath.startswith('typeshed/'):
+            # We don't track changes to typeshed -- the assumption is that they are only changed
+            # as part of mypy updates, which will invalidate everything anyway.
+            #
+            # TODO: Not a reliable test, as we could have a package named typeshed.
+            # TODO: Consider relaxing this -- maybe allow some typeshed changes to be tracked.
+            return
+        self.fine_grained_deps = get_dependencies(target=self.tree,
+                                                  type_map=self.type_map(),
+                                                  python_version=self.options.python_version)
+
     def valid_references(self) -> Set[str]:
         assert self.ancestors is not None
         valid_refs = set(self.dependencies + self.suppressed + self.ancestors)
@@ -2003,6 +2025,7 @@ def write_cache(self) -> None:
         dep_prios = self.dependency_priorities()
         new_interface_hash, self.meta = write_cache(
             self.id, self.path, self.tree,
+            {k: list(v) for k, v in self.fine_grained_deps.items()},
             list(self.dependencies), list(self.suppressed), list(self.child_modules),
             dep_prios, self.interface_hash, self.source_hash, self.ignore_all,
             self.manager)
@@ -2534,6 +2557,8 @@ def process_stale_scc(graph: Graph, scc: List[str], manager: BuildManager) -> No
             graph[id].transitive_error = True
     for id in stale:
         graph[id].finish_passes()
+        if manager.options.cache_fine_grained:
+            graph[id].compute_fine_grained_deps()
         graph[id].generate_unused_ignore_notes()
         manager.flush_errors(manager.errors.file_messages(graph[id].xpath), False)
         graph[id].write_cache()

mypy/main.py

@@ -320,6 +320,8 @@ def add_invertible_flag(flag: str,
     parser.add_argument('--cache-dir', action='store', metavar='DIR',
                         help="store module cache info in the given folder in incremental mode "
                         "(defaults to '{}')".format(defaults.CACHE_DIR))
+    parser.add_argument('--cache-fine-grained', action='store_true',
+                        help="include fine-grained dependency information in the cache")
     parser.add_argument('--skip-version-check', action='store_true',
                         help="allow using cache written by older mypy version")
     add_invertible_flag('--strict-optional', default=False, strict_flag=True,

mypy/options.py

@@ -42,7 +42,8 @@ class Options:
         "disallow_untyped_decorators",
     }
 
-    OPTIONS_AFFECTING_CACHE = ((PER_MODULE_OPTIONS | {"quick_and_dirty", "platform"})
+    OPTIONS_AFFECTING_CACHE = ((PER_MODULE_OPTIONS |
+                                {"quick_and_dirty", "platform", "cache_fine_grained"})
                                - {"debug_cache"})
 
     def __init__(self) -> None:
@@ -142,6 +143,7 @@ def __init__(self) -> None:
         self.quick_and_dirty = False
         self.skip_version_check = False
         self.fine_grained_incremental = False
+        self.cache_fine_grained = False
 
         # Paths of user plugins
         self.plugins = []  # type: List[str]

mypy/server/update.py

@@ -280,7 +280,7 @@ def update_single(self, module: str, path: str) -> Tuple[List[str],
                         if not trigger.endswith('__>')]
             print('triggered:', sorted(filtered))
         self.triggered.extend(triggered | self.previous_targets_with_errors)
-        update_dependencies({module: tree}, self.deps, graph, self.options)
+        collect_dependencies({module: tree}, self.deps, graph)
         propagate_changes_using_dependencies(manager, graph, self.deps, triggered,
                                              {module},
                                              self.previous_targets_with_errors)
@@ -319,7 +319,7 @@ def get_all_dependencies(manager: BuildManager, graph: Dict[str, State],
                          options: Options) -> Dict[str, Set[str]]:
     """Return the fine-grained dependency map for an entire build."""
     deps = {}  # type: Dict[str, Set[str]]
-    update_dependencies(manager.modules, deps, graph, options)
+    collect_dependencies(manager.modules, deps, graph)
     return deps
 
 
@@ -644,24 +644,14 @@ def find_import_line(node: MypyFile, target: str) -> Optional[int]:
     return None
 
 
-def update_dependencies(new_modules: Mapping[str, Optional[MypyFile]],
-                        deps: Dict[str, Set[str]],
-                        graph: Dict[str, State],
-                        options: Options) -> None:
+def collect_dependencies(new_modules: Mapping[str, Optional[MypyFile]],
+                         deps: Dict[str, Set[str]],
+                         graph: Dict[str, State]) -> None:
     for id, node in new_modules.items():
         if node is None:
             continue
-        if '/typeshed/' in node.path or node.path.startswith('typeshed/'):
-            # We don't track changes to typeshed -- the assumption is that they are only changed
-            # as part of mypy updates, which will invalidate everything anyway.
-            #
-            # TODO: Not a reliable test, as we could have a package named typeshed.
-            # TODO: Consider relaxing this -- maybe allow some typeshed changes to be tracked.
-            continue
-        module_deps = get_dependencies(target=node,
-                                       type_map=graph[id].type_map(),
-                                       python_version=options.python_version)
-        for trigger, targets in module_deps.items():
+        graph[id].compute_fine_grained_deps()
+        for trigger, targets in graph[id].fine_grained_deps.items():
             deps.setdefault(trigger, set()).update(targets)