Add warn-unreachable to strict mode

docs/source/command_line.rst

@@ -813,9 +813,6 @@ of the above sections.
     strict will catch type errors as long as intentional methods like type ignore
     or casting were not used.)
 
-    Note: the :option:`--warn-unreachable` flag
-    is not automatically enabled by the strict flag.
-
     The strict flag does not take precedence over other strict-related flags.
     Directly specifying a flag of alternate behavior will override the
     behavior of strict, regardless of the order in which they are passed.

mypy/main.py

@@ -837,7 +837,7 @@ def add_invertible_flag(
     add_invertible_flag(
         "--warn-unreachable",
         default=False,
-        strict_flag=False,
+        strict_flag=True,
         help="Warn about statements or expressions inferred to be unreachable",
         group=lint_group,
     )

mypy_self_check.ini

@@ -12,5 +12,4 @@ exclude = mypy/typeshed/|mypyc/test-data/|mypyc/lib-rt/
 enable_error_code = ignore-without-code,redundant-expr
 enable_incomplete_feature = PreciseTupleTypes
 show_error_code_links = True
-warn_unreachable = True
 fixed_format_cache = True