Merge branch 'master' into patch-22

Author: BobTheBuidler

CHANGELOG.md

@@ -11,6 +11,27 @@ Support for this will be dropped in the first half of 2026!
 
 Contributed by Marc Mueller (PR [20156](https://github.com/python/mypy/pull/20156)).
 
+### Mypyc Accelerated Mypy Wheels for ARM Windows and Free Threading
+
+For best performance, mypy can be compiled to C extension modules using mypyc. This makes
+mypy 3-5x faster than when interpreted with pure Python. We now build and upload mypyc
+accelerated mypy wheels for `win_arm64` and `cp314t-...` to PyPI, making it easy for Windows
+users on ARM and those using the free theading builds for Python 3.14 to realise this speedup
+-- just `pip install` the latest mypy.
+
+Contributed by Marc Mueller
+(PR [mypy_mypyc-wheels#106](https://github.com/mypyc/mypy_mypyc-wheels/pull/106),
+PR [mypy_mypyc-wheels#110](https://github.com/mypyc/mypy_mypyc-wheels/pull/110)).
+
+### Removed flags `--force-uppercase-builtins` and `--force-union-syntax`
+
+The `--force-uppercase-builtins` flag was deprecated and has been a no-op since mypy 1.17.0.
+Since mypy has dropped support for Python 3.9, the `--force-union-syntax` flag is no longer
+necessary.
+
+Contributed by Marc Mueller (PR [20410](https://github.com/python/mypy/pull/20410))
+and (PR [20405](https://github.com/python/mypy/pull/20405)).
+
 ## Mypy 1.19
 
 We’ve just uploaded mypy 1.19.0 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)).
@@ -216,6 +237,17 @@ Related PRs:
 
 Please see [git log](https://github.com/python/typeshed/commits/main?after=ebce8d766b41fbf4d83cf47c1297563a9508ff60+0&branch=main&path=stdlib) for full list of standard library typeshed stub changes.
 
+### Mypy 1.19.1
+
+- Fix noncommutative joins with bounded TypeVars (Shantanu, PR [20345](https://github.com/python/mypy/pull/20345))
+- Respect output format for cached runs by serializing raw errors in cache metas (Ivan Levkivskyi, PR [20372](https://github.com/python/mypy/pull/20372))
+- Allow `types.NoneType` in match cases (A5rocks, PR [20383](https://github.com/python/mypy/pull/20383))
+- Fix mypyc generator regression with empty tuple (BobTheBuidler, PR [20371](https://github.com/python/mypy/pull/20371))
+- Fix crash involving Unpack-ed TypeVarTuple (Shantanu, PR [20323](https://github.com/python/mypy/pull/20323))
+- Fix crash on star import of redefinition (Ivan Levkivskyi, PR [20333](https://github.com/python/mypy/pull/20333))
+- Fix crash on typevar with forward ref used in other module (Ivan Levkivskyi, PR [20334](https://github.com/python/mypy/pull/20334))
+- Fail with an explicit error on PyPy (Ivan Levkivskyi, PR [20389](https://github.com/python/mypy/pull/20389))
+
 ### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:
@@ -251,7 +283,7 @@ Thanks to all mypy contributors who contributed to this release:
 
 I’d also like to thank my employer, Dropbox, for supporting mypy development.
 
-## Mypy 1.18.1
+## Mypy 1.18
 
 We’ve just uploaded mypy 1.18.1 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)).
 Mypy is a static type checker for Python. This release includes new features, performance

docs/source/additional_features.rst

@@ -135,7 +135,7 @@ Type annotations can be added as follows:
 
 .. code-block:: python
 
-    import attr
+    import attrs
 
     @attrs.define
     class A:

docs/source/command_line.rst

@@ -958,12 +958,6 @@ in error messages.
     useful or they may be overly noisy. If ``N`` is negative, there is
     no limit. The default limit is -1.
 
-.. option:: --force-union-syntax
-
-    Always use ``Union[]`` and ``Optional[]`` for union types
-    in error messages (instead of the ``|`` operator),
-    even on Python 3.10+.
-
 
 .. _incremental:
 

docs/source/config_file.rst

@@ -930,15 +930,6 @@ These options may only be set in the global section (``[mypy]``).
 
     Show absolute paths to files.
 
-.. confval:: force_union_syntax
-
-    :type: boolean
-    :default: False
-
-    Always use ``Union[]`` and ``Optional[]`` for union types
-    in error messages (instead of the ``|`` operator),
-    even on Python 3.10+.
-
 Incremental mode
 ****************
 

docs/source/error_code_list2.rst

@@ -32,7 +32,7 @@ Example:
 
     # mypy: disallow-any-generics
 
-    # Error: Missing type parameters for generic type "list"  [type-arg]
+    # Error: Missing type arguments for generic type "list"  [type-arg]
     def remove_dups(items: list) -> list:
         ...
 

mypy-requirements.txt

@@ -4,4 +4,4 @@ typing_extensions>=4.6.0
 mypy_extensions>=1.0.0
 pathspec>=0.9.0
 tomli>=1.1.0; python_version<'3.11'
-librt>=0.6.2
+librt>=0.6.2; platform_python_implementation != 'PyPy'

mypy/build.py

@@ -43,7 +43,14 @@
 from librt.internal import cache_version
 
 import mypy.semanal_main
-from mypy.cache import CACHE_VERSION, CacheMeta, ReadBuffer, WriteBuffer, write_json
+from mypy.cache import (
+    CACHE_VERSION,
+    CacheMeta,
+    ReadBuffer,
+    SerializedError,
+    WriteBuffer,
+    write_json,
+)
 from mypy.checker import TypeChecker
 from mypy.defaults import (
     WORKER_CONNECTION_TIMEOUT,
@@ -52,7 +59,7 @@
     WORKER_START_TIMEOUT,
 )
 from mypy.error_formatter import OUTPUT_CHOICES, ErrorFormatter
-from mypy.errors import CompileError, ErrorInfo, Errors, report_internal_error
+from mypy.errors import CompileError, ErrorInfo, Errors, ErrorTuple, report_internal_error
 from mypy.graph_utils import prepare_sccs, strongly_connected_components, topsort
 from mypy.indirection import TypeIndirectionVisitor
 from mypy.ipc import BadStatus, IPCClient, read_status, ready_to_read, receive, send
@@ -2046,7 +2053,7 @@ class State:
     dep_hashes: dict[str, bytes] = {}
 
     # List of errors reported for this file last time.
-    error_lines: list[str] = []
+    error_lines: list[SerializedError] = []
 
     # Parent package, its parent, etc.
     ancestors: list[str] | None = None
@@ -2173,7 +2180,8 @@ def __init__(
             self.dep_hashes = {
                 k: v for (k, v) in zip(self.meta.dependencies, self.meta.dep_hashes)
             }
-            self.error_lines = self.meta.error_lines
+            # Only copy `error_lines` if the module is not silently imported.
+            self.error_lines = [] if self.ignore_all else self.meta.error_lines
             if temporary:
                 self.load_tree(temporary=True)
             if not manager.use_fine_grained_cache():
@@ -3511,9 +3519,13 @@ def find_stale_sccs(
                 scc = order_ascc_ex(graph, ascc)
             for id in scc:
                 if graph[id].error_lines:
-                    manager.flush_errors(
-                        manager.errors.simplify_path(graph[id].xpath), graph[id].error_lines, False
+                    path = manager.errors.simplify_path(graph[id].xpath)
+                    formatted = manager.errors.format_messages(
+                        path,
+                        deserialize_codes(graph[id].error_lines),
+                        formatter=manager.error_formatter,
                     )
+                    manager.flush_errors(path, formatted, False)
             fresh_sccs.append(ascc)
         else:
             size = len(ascc.mod_ids)
@@ -3759,21 +3771,24 @@ def process_stale_scc(
     # Flush errors, and write cache in two phases: first data files, then meta files.
     meta_tuples = {}
     errors_by_id = {}
+    formatted_by_id = {}
     for id in stale:
         if graph[id].xpath not in manager.errors.ignored_files:
-            errors = manager.errors.file_messages(
-                graph[id].xpath, formatter=manager.error_formatter
+            errors = manager.errors.file_messages(graph[id].xpath)
+            formatted = manager.errors.format_messages(
+                graph[id].xpath, errors, formatter=manager.error_formatter
             )
-            manager.flush_errors(manager.errors.simplify_path(graph[id].xpath), errors, False)
+            manager.flush_errors(manager.errors.simplify_path(graph[id].xpath), formatted, False)
             errors_by_id[id] = errors
+            formatted_by_id[id] = formatted
         meta_tuples[id] = graph[id].write_cache()
     for id in stale:
         meta_tuple = meta_tuples[id]
         if meta_tuple is None:
             continue
         meta, meta_file = meta_tuple
         meta.dep_hashes = [graph[dep].interface_hash for dep in graph[id].dependencies]
-        meta.error_lines = errors_by_id.get(id, [])
+        meta.error_lines = serialize_codes(errors_by_id.get(id, []))
         write_cache_meta(meta, manager, meta_file)
     manager.done_sccs.add(ascc.id)
     manager.add_stats(
@@ -3785,7 +3800,7 @@ def process_stale_scc(
     )
     scc_result = {}
     for id in scc:
-        scc_result[id] = graph[id].interface_hash.hex(), errors_by_id.get(id, [])
+        scc_result[id] = graph[id].interface_hash.hex(), formatted_by_id.get(id, [])
     return scc_result
 
 
@@ -3932,3 +3947,26 @@ def sccs_to_bytes(sccs: list[SCC]) -> bytes:
     buf = WriteBuffer()
     write_json(buf, {"sccs": scc_tuples})
     return buf.getvalue()
+
+
+def serialize_codes(errs: list[ErrorTuple]) -> list[SerializedError]:
+    return [
+        (path, line, column, end_line, end_column, severity, message, code.code if code else None)
+        for path, line, column, end_line, end_column, severity, message, code in errs
+    ]
+
+
+def deserialize_codes(errs: list[SerializedError]) -> list[ErrorTuple]:
+    return [
+        (
+            path,
+            line,
+            column,
+            end_line,
+            end_column,
+            severity,
+            message,
+            codes.error_codes.get(code) if code else None,
+        )
+        for path, line, column, end_line, end_column, severity, message, code in errs
+    ]

mypy/cache.py

@@ -69,7 +69,9 @@
 from mypy_extensions import u8
 
 # High-level cache layout format
-CACHE_VERSION: Final = 0
+CACHE_VERSION: Final = 1
+
+SerializedError: _TypeAlias = tuple[str | None, int, int, int, int, str, str, str | None]
 
 
 class CacheMeta:
@@ -92,7 +94,7 @@ def __init__(
         dep_lines: list[int],
         dep_hashes: list[bytes],
         interface_hash: bytes,
-        error_lines: list[str],
+        error_lines: list[SerializedError],
         version_id: str,
         ignore_all: bool,
         plugin_data: Any,
@@ -157,7 +159,7 @@ def deserialize(cls, meta: dict[str, Any], data_file: str) -> CacheMeta | None:
                 dep_lines=meta["dep_lines"],
                 dep_hashes=[bytes.fromhex(dep) for dep in meta["dep_hashes"]],
                 interface_hash=bytes.fromhex(meta["interface_hash"]),
-                error_lines=meta["error_lines"],
+                error_lines=[tuple(err) for err in meta["error_lines"]],
                 version_id=meta["version_id"],
                 ignore_all=meta["ignore_all"],
                 plugin_data=meta["plugin_data"],
@@ -179,7 +181,7 @@ def write(self, data: WriteBuffer) -> None:
         write_int_list(data, self.dep_lines)
         write_bytes_list(data, self.dep_hashes)
         write_bytes(data, self.interface_hash)
-        write_str_list(data, self.error_lines)
+        write_errors(data, self.error_lines)
         write_str(data, self.version_id)
         write_bool(data, self.ignore_all)
         # Plugin data may be not a dictionary, so we use
@@ -204,7 +206,7 @@ def read(cls, data: ReadBuffer, data_file: str) -> CacheMeta | None:
                 dep_lines=read_int_list(data),
                 dep_hashes=read_bytes_list(data),
                 interface_hash=read_bytes(data),
-                error_lines=read_str_list(data),
+                error_lines=read_errors(data),
                 version_id=read_str(data),
                 ignore_all=read_bool(data),
                 plugin_data=read_json_value(data),
@@ -231,6 +233,7 @@ def read(cls, data: ReadBuffer, data_file: str) -> CacheMeta | None:
 LIST_INT: Final[Tag] = 21
 LIST_STR: Final[Tag] = 22
 LIST_BYTES: Final[Tag] = 23
+TUPLE_GEN: Final[Tag] = 24
 DICT_STR_GEN: Final[Tag] = 30
 
 # Misc classes.
@@ -391,12 +394,11 @@ def write_str_opt_list(data: WriteBuffer, value: list[str | None]) -> None:
 
 
 Value: _TypeAlias = None | int | str | bool
-JsonValue: _TypeAlias = Value | list["JsonValue"] | dict[str, "JsonValue"]
 
-# Currently tuples are used by mypyc plugin. They will be normalized to
-# JSON lists after a roundtrip.
-JsonValueEx: _TypeAlias = (
-    Value | list["JsonValueEx"] | dict[str, "JsonValueEx"] | tuple["JsonValueEx", ...]
+# Our JSON format is somewhat non-standard as we distinguish lists and tuples.
+# This is convenient for some internal things, like mypyc plugin and error serialization.
+JsonValue: _TypeAlias = (
+    Value | list["JsonValue"] | dict[str, "JsonValue"] | tuple["JsonValue", ...]
 )
 
 
@@ -415,13 +417,16 @@ def read_json_value(data: ReadBuffer) -> JsonValue:
     if tag == LIST_GEN:
         size = read_int_bare(data)
         return [read_json_value(data) for _ in range(size)]
+    if tag == TUPLE_GEN:
+        size = read_int_bare(data)
+        return tuple(read_json_value(data) for _ in range(size))
     if tag == DICT_STR_GEN:
         size = read_int_bare(data)
         return {read_str_bare(data): read_json_value(data) for _ in range(size)}
     assert False, f"Invalid JSON tag: {tag}"
 
 
-def write_json_value(data: WriteBuffer, value: JsonValueEx) -> None:
+def write_json_value(data: WriteBuffer, value: JsonValue) -> None:
     if value is None:
         write_tag(data, LITERAL_NONE)
     elif isinstance(value, bool):
@@ -432,11 +437,16 @@ def write_json_value(data: WriteBuffer, value: JsonValueEx) -> None:
     elif isinstance(value, str):
         write_tag(data, LITERAL_STR)
         write_str_bare(data, value)
-    elif isinstance(value, (list, tuple)):
+    elif isinstance(value, list):
         write_tag(data, LIST_GEN)
         write_int_bare(data, len(value))
         for val in value:
             write_json_value(data, val)
+    elif isinstance(value, tuple):
+        write_tag(data, TUPLE_GEN)
+        write_int_bare(data, len(value))
+        for val in value:
+            write_json_value(data, val)
     elif isinstance(value, dict):
         write_tag(data, DICT_STR_GEN)
         write_int_bare(data, len(value))
@@ -461,3 +471,38 @@ def write_json(data: WriteBuffer, value: dict[str, Any]) -> None:
     for key in sorted(value):
         write_str_bare(data, key)
         write_json_value(data, value[key])
+
+
+def write_errors(data: WriteBuffer, errs: list[SerializedError]) -> None:
+    write_tag(data, LIST_GEN)
+    write_int_bare(data, len(errs))
+    for path, line, column, end_line, end_column, severity, message, code in errs:
+        write_tag(data, TUPLE_GEN)
+        write_str_opt(data, path)
+        write_int(data, line)
+        write_int(data, column)
+        write_int(data, end_line)
+        write_int(data, end_column)
+        write_str(data, severity)
+        write_str(data, message)
+        write_str_opt(data, code)
+
+
+def read_errors(data: ReadBuffer) -> list[SerializedError]:
+    assert read_tag(data) == LIST_GEN
+    result = []
+    for _ in range(read_int_bare(data)):
+        assert read_tag(data) == TUPLE_GEN
+        result.append(
+            (
+                read_str_opt(data),
+                read_int(data),
+                read_int(data),
+                read_int(data),
+                read_int(data),
+                read_str(data),
+                read_str(data),
+                read_str_opt(data),
+            )
+        )
+    return result