init

.venv/lib/python3.8/site-packages/mypy/server/mergecheck.py

@@ -0,0 +1,82 @@
+"""Check for duplicate AST nodes after merge."""
+
+from typing import Dict, List, Tuple
+from typing_extensions import Final
+
+from mypy.nodes import FakeInfo, SymbolNode, Var, Decorator, FuncDef
+from mypy.server.objgraph import get_reachable_graph, get_path
+
+# If True, print more verbose output on failure.
+DUMP_MISMATCH_NODES: Final = False
+
+
+def check_consistency(o: object) -> None:
+    """Fail if there are two AST nodes with the same fullname reachable from 'o'.
+
+    Raise AssertionError on failure and print some debugging output.
+    """
+    seen, parents = get_reachable_graph(o)
+    reachable = list(seen.values())
+    syms = [x for x in reachable if isinstance(x, SymbolNode)]
+
+    m: Dict[str, SymbolNode] = {}
+    for sym in syms:
+        if isinstance(sym, FakeInfo):
+            continue
+
+        fn = sym.fullname
+        # Skip None names, since they are ambiguous.
+        # TODO: Everything should have a proper full name?
+        if fn is None:
+            continue
+        # Skip stuff that should be expected to have duplicate names
+        if isinstance(sym, (Var, Decorator)):
+            continue
+        if isinstance(sym, FuncDef) and sym.is_overload:
+            continue
+
+        if fn not in m:
+            m[sym.fullname] = sym
+            continue
+
+        # We have trouble and need to decide what to do about it.
+        sym1, sym2 = sym, m[fn]
+
+        # If the type changed, then it shouldn't have been merged.
+        if type(sym1) is not type(sym2):
+            continue
+
+        path1 = get_path(sym1, seen, parents)
+        path2 = get_path(sym2, seen, parents)
+
+        if fn in m:
+            print('\nDuplicate %r nodes with fullname %r found:' % (type(sym).__name__, fn))
+            print('[1] %d: %s' % (id(sym1), path_to_str(path1)))
+            print('[2] %d: %s' % (id(sym2), path_to_str(path2)))
+
+        if DUMP_MISMATCH_NODES and fn in m:
+            # Add verbose output with full AST node contents.
+            print('---')
+            print(id(sym1), sym1)
+            print('---')
+            print(id(sym2), sym2)
+
+        assert sym.fullname not in m
+
+
+def path_to_str(path: List[Tuple[object, object]]) -> str:
+    result = '<root>'
+    for attr, obj in path:
+        t = type(obj).__name__
+        if t in ('dict', 'tuple', 'SymbolTable', 'list'):
+            result += '[%s]' % repr(attr)
+        else:
+            if isinstance(obj, Var):
+                result += '.%s(%s:%s)' % (attr, t, obj.name)
+            elif t in ('BuildManager', 'FineGrainedBuildManager'):
+                # Omit class name for some classes that aren't part of a class
+                # hierarchy since there isn't much ambiguity.
+                result += '.%s' % attr
+            else:
+                result += '.%s(%s)' % (attr, t)
+    return result