Merge remote-tracking branch 'upstream/master' into bugfix/gh-19454-ops-on-typevr

Author: sterliakov

.github/ISSUE_TEMPLATE/crash.md

@@ -15,7 +15,7 @@ labels: "crash"
 
 **Traceback**
 
-```
+```python-traceback
 (Insert traceback and other messages from mypy here -- use `--show-traceback`.)
 ```
 
@@ -25,6 +25,11 @@ labels: "crash"
 appreciated.  We also very much appreciate it if you try to narrow the
 source down to a small stand-alone example.)
 
+```python
+# Ideally, a small sample program that demonstrates the problem.
+# Or even better, a reproducible playground link https://mypy-play.net/ (use the "Gist" button)
+```
+
 **Your Environment**
 
 <!-- Include as many relevant details about the environment you experienced the bug in -->

.github/workflows/test.yml

@@ -37,11 +37,6 @@ jobs:
           toxenv: py
           tox_extra_args: "-n 4"
           test_mypyc: true
-        - name: Test suite with py39-windows-64
-          python: '3.9'
-          os: windows-latest
-          toxenv: py39
-          tox_extra_args: "-n 4"
         - name: Test suite with py310-ubuntu
           python: '3.10'
           os: ubuntu-24.04-arm
@@ -64,6 +59,11 @@ jobs:
           toxenv: py
           tox_extra_args: "-n 4"
           test_mypyc: true
+        - name: Test suite with py313-windows-64
+          python: '3.13'
+          os: windows-latest
+          toxenv: py
+          tox_extra_args: "-n 4"
 
         - name: Test suite with py314-dev-ubuntu
           python: '3.14-dev'

CHANGELOG.md

@@ -170,6 +170,11 @@ Related PRs:
 * Enable ANSI color codes for dmypy client in Windows (wyattscarpenter, PR [19088](https://github.com/python/mypy/pull/19088))
 * Extend special case for context-based type variable inference to unions in return position (Stanislav Terliakov, PR [18976](https://github.com/python/mypy/pull/18976))
 
+### Mypy 1.17.1
+* Retain `None` as constraints bottom if no bottoms were provided (Stanislav Terliakov, PR [19485](https://github.com/python/mypy/pull/19485))
+* Fix "ignored exception in `hasattr`" in dmypy (Stanislav Terliakov, PR [19428](https://github.com/python/mypy/pull/19428))
+* Prevent a crash when InitVar is redefined with a method in a subclass (Stanislav Terliakov, PR [19453](https://github.com/python/mypy/pull/19453))
+
 ### Acknowledgements
 
 Thanks to all mypy contributors who contributed to this release:

docs/source/command_line.rst

@@ -812,6 +812,14 @@ of the above sections.
     Note: the exact list of flags enabled by running :option:`--strict` may change
     over time.
 
+    .. include:: strict_list.rst
+    ..
+        The above file is autogenerated and included during html generation.
+        (That's an include directive, and this is a comment.)
+        It would be fine to generate it at some other time instead,
+        theoretically, but we already had a convenient hook during html gen.
+
+
 .. option:: --disable-error-code
 
     This flag allows disabling one or multiple error codes globally.

docs/source/common_issues.rst

@@ -218,6 +218,14 @@ daemon <mypy_daemon>`, which can speed up incremental mypy runtimes by
 a factor of 10 or more. :ref:`Remote caching <remote-cache>` can
 make cold mypy runs several times faster.
 
+Furthermore: as of `mypy 1.13 <https://mypy-lang.blogspot.com/2024/10/mypy-113-released.html>`_,
+mypy allows use of the orjson library for handling the cache instead of the stdlib json, for
+improved performance. You can ensure the presence of orjson using the faster-cache extra:
+
+    python3 -m pip install -U mypy[faster-cache]
+
+Mypy may depend on orjson by default in the future.
+
 Types of empty collections
 --------------------------
 
@@ -505,11 +513,15 @@ to see the types of all local variables at once. Example:
    #     b: builtins.str
 .. note::
 
-   ``reveal_type`` and ``reveal_locals`` are only understood by mypy and
-   don't exist in Python. If you try to run your program, you'll have to
-   remove any ``reveal_type`` and ``reveal_locals`` calls before you can
-   run your code. Both are always available and you don't need to import
-   them.
+    ``reveal_type`` and ``reveal_locals`` are handled specially by mypy during
+    type checking, and don't have to be defined or imported.
+
+    However, if you want to run your code,
+    you'll have to remove any ``reveal_type`` and ``reveal_locals``
+    calls from your program or else Python will give you an error at runtime.
+
+    Alternatively, you can import ``reveal_type`` from ``typing_extensions``
+    or ``typing`` (on Python 3.11 and newer)
 
 .. _silencing-linters:
 

docs/source/conf.py

@@ -278,9 +278,9 @@
 intersphinx_mapping = {
     "python": ("https://docs.python.org/3", None),
     "attrs": ("https://www.attrs.org/en/stable/", None),
-    "cython": ("https://docs.cython.org/en/latest", None),
+    "cython": ("https://cython.readthedocs.io/en/stable", None),
     "monkeytype": ("https://monkeytype.readthedocs.io/en/latest", None),
-    "setuptools": ("https://setuptools.readthedocs.io/en/latest", None),
+    "setuptools": ("https://setuptools.pypa.io/en/latest", None),
 }
 
 

docs/source/dynamic_typing.rst

@@ -1,6 +1,5 @@
 .. _dynamic-typing:
 
-
 Dynamically typed code
 ======================
 
@@ -94,6 +93,8 @@ third party libraries that mypy does not know about. This is particularly the ca
 when using the :option:`--ignore-missing-imports <mypy --ignore-missing-imports>`
 flag. See :ref:`fix-missing-imports` for more information about this.
 
+.. _any-vs-object:
+
 Any vs. object
 --------------
 

docs/source/html_builder.py

@@ -11,16 +11,37 @@
 from sphinx.builders.html import StandaloneHTMLBuilder
 from sphinx.environment import BuildEnvironment
 
+from mypy.main import define_options
+
 
 class MypyHTMLBuilder(StandaloneHTMLBuilder):
+    strict_file: Path
+
     def __init__(self, app: Sphinx, env: BuildEnvironment) -> None:
         super().__init__(app, env)
         self._ref_to_doc = {}
+        self.strict_file = Path(self.srcdir) / "strict_list.rst"
+        self._add_strict_list()
 
     def write_doc(self, docname: str, doctree: document) -> None:
         super().write_doc(docname, doctree)
         self._ref_to_doc.update({_id: docname for _id in doctree.ids})
 
+    def _add_strict_list(self) -> None:
+        strict_flags: list[str]
+        _, strict_flags, _ = define_options()
+        strict_part = ", ".join(f":option:`{s} <mypy {s}>`" for s in strict_flags)
+        if (
+            not strict_part
+            or strict_part.isspace()
+            or len(strict_part) < 20
+            or len(strict_part) > 2000
+        ):
+            raise ValueError(f"{strict_part=}, which doesn't look right (by a simple heuristic).")
+        self.strict_file.write_text(
+            "For this version of mypy, the list of flags enabled by strict is: " + strict_part
+        )
+
     def _verify_error_codes(self) -> None:
         from mypy.errorcodes import error_codes
 
@@ -55,6 +76,7 @@ def _write_ref_redirector(self) -> None:
     def finish(self) -> None:
         super().finish()
         self._write_ref_redirector()
+        self.strict_file.unlink()
 
 
 def setup(app: Sphinx) -> dict[str, Any]:

docs/source/kinds_of_types.rst

@@ -41,6 +41,11 @@ operations are permitted on the value, and the operations are only checked
 at runtime. You can use ``Any`` as an "escape hatch" when you can't use
 a more precise type for some reason.
 
+This should not be confused with the
+:py:class:`object` type, which represents the set of all values.
+Unlike ``object``, ``Any`` introduces type unsafety — see
+:ref:`any-vs-object` for more.
+
 ``Any`` is compatible with every other type, and vice versa. You can freely
 assign a value of type ``Any`` to a variable with a more precise type:
 

misc/log_trace_check.py

@@ -0,0 +1,85 @@
+"""Compile mypy using mypyc with trace logging enabled, and collect a trace.
+
+The trace log can be used to analyze low-level performance bottlenecks.
+
+By default does a self check as the workload.
+
+This works on all supported platforms, unlike some of our other performance tools.
+"""
+
+from __future__ import annotations
+
+import argparse
+import glob
+import os
+import shutil
+import subprocess
+import sys
+import time
+
+from perf_compare import build_mypy, clone
+
+# Generated files, including binaries, go under this directory to avoid overwriting user state.
+TARGET_DIR = "mypy.log_trace.tmpdir"
+
+
+def perform_type_check(target_dir: str, code: str | None) -> None:
+    cache_dir = os.path.join(target_dir, ".mypy_cache")
+    if os.path.exists(cache_dir):
+        shutil.rmtree(cache_dir)
+    args = []
+    if code is None:
+        args.extend(["--config-file", "mypy_self_check.ini"])
+        for pat in "mypy/*.py", "mypy/*/*.py", "mypyc/*.py", "mypyc/test/*.py":
+            args.extend(glob.glob(pat))
+    else:
+        args.extend(["-c", code])
+    check_cmd = ["python", "-m", "mypy"] + args
+    t0 = time.time()
+    subprocess.run(check_cmd, cwd=target_dir, check=True)
+    elapsed = time.time() - t0
+    print(f"{elapsed:.2f}s elapsed")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Compile mypy and collect a trace log while type checking (by default, self check)."
+    )
+    parser.add_argument(
+        "--multi-file",
+        action="store_true",
+        help="compile mypy into one C file per module (to reduce RAM use during compilation)",
+    )
+    parser.add_argument(
+        "--skip-compile", action="store_true", help="use compiled mypy from previous run"
+    )
+    parser.add_argument(
+        "-c",
+        metavar="CODE",
+        default=None,
+        type=str,
+        help="type check Python code fragment instead of mypy self-check",
+    )
+    args = parser.parse_args()
+    multi_file: bool = args.multi_file
+    skip_compile: bool = args.skip_compile
+    code: str | None = args.c
+
+    target_dir = TARGET_DIR
+
+    if not skip_compile:
+        clone(target_dir, "HEAD")
+
+        print(f"Building mypy in {target_dir} with trace logging enabled...")
+        build_mypy(target_dir, multi_file, log_trace=True, opt_level="0")
+    elif not os.path.isdir(target_dir):
+        sys.exit("error: Can't find compile mypy from previous run -- can't use --skip-compile")
+
+    perform_type_check(target_dir, code)
+
+    trace_fnam = os.path.join(target_dir, "mypyc_trace.txt")
+    print(f"Generated event trace log in {trace_fnam}")
+
+
+if __name__ == "__main__":
+    main()