Merge remote-tracking branch 'upstream/main' into perf/hashlib/mutex-135239

# Conflicts:
#	Modules/hmacmodule.c

Author: picnixz

.github/CODEOWNERS

@@ -35,6 +35,7 @@ Objects/type*                 @markshannon
 Objects/codeobject.c          @markshannon
 Objects/frameobject.c         @markshannon
 Objects/call.c                @markshannon
+Objects/object.c              @ZeroIntensity
 Python/ceval*.c               @markshannon
 Python/ceval*.h               @markshannon
 Python/codegen.c              @markshannon @iritkatriel
@@ -44,8 +45,9 @@ Python/flowgraph.c            @markshannon @iritkatriel
 Python/instruction_sequence.c @iritkatriel
 Python/bytecodes.c            @markshannon
 Python/optimizer*.c           @markshannon
-Python/optimizer_analysis.c   @Fidget-Spinner
-Python/optimizer_bytecodes.c  @Fidget-Spinner
+Python/optimizer_analysis.c   @Fidget-Spinner @tomasr8
+Python/optimizer_bytecodes.c  @Fidget-Spinner @tomasr8
+Python/optimizer_symbols.c    @tomasr8
 Python/symtable.c             @JelleZijlstra @carljm
 Lib/_pyrepl/*                 @pablogsal @lysnikolaou @ambv
 Lib/test/test_patma.py        @brandtbucher
@@ -66,8 +68,8 @@ Doc/_static/**                @AA-Turner @hugovk
 Doc/tools/**                  @AA-Turner @hugovk
 
 # runtime state/lifecycle
-**/*pylifecycle*              @ericsnowcurrently
-**/*pystate*                  @ericsnowcurrently
+**/*pylifecycle*              @ericsnowcurrently @ZeroIntensity
+**/*pystate*                  @ericsnowcurrently @ZeroIntensity
 **/*preconfig*                @ericsnowcurrently
 **/*initconfig*               @ericsnowcurrently
 **/*pathconfig*               @ericsnowcurrently
@@ -187,13 +189,13 @@ Include/internal/pycore_time.h  @pganssle @abalkin
 /Tools/cases_generator/        @markshannon
 
 # AST
-Python/ast.c                  @isidentical @JelleZijlstra @eclips4
-Python/ast_preprocess.c       @isidentical @eclips4
-Parser/asdl.py                @isidentical @JelleZijlstra @eclips4
-Parser/asdl_c.py              @isidentical @JelleZijlstra @eclips4
-Lib/ast.py                    @isidentical @JelleZijlstra @eclips4
-Lib/_ast_unparse.py           @isidentical @JelleZijlstra @eclips4
-Lib/test/test_ast/            @eclips4
+Python/ast.c                  @isidentical @JelleZijlstra @eclips4 @tomasr8
+Python/ast_preprocess.c       @isidentical @eclips4 @tomasr8
+Parser/asdl.py                @isidentical @JelleZijlstra @eclips4 @tomasr8
+Parser/asdl_c.py              @isidentical @JelleZijlstra @eclips4 @tomasr8
+Lib/ast.py                    @isidentical @JelleZijlstra @eclips4 @tomasr8
+Lib/_ast_unparse.py           @isidentical @JelleZijlstra @eclips4 @tomasr8
+Lib/test/test_ast/            @eclips4 @tomasr8
 
 # Mock
 /Lib/unittest/mock.py         @cjw296
@@ -340,3 +342,6 @@ Modules/_xxtestfuzz/          @ammaraskar
 Python/remote_debug.h         @pablogsal
 Python/remote_debugging.c     @pablogsal
 Modules/_remote_debugging_module.c @pablogsal @ambv @1st1
+
+# gettext
+**/*gettext*                  @tomasr8

.github/workflows/build.yml

@@ -527,6 +527,14 @@ jobs:
       config_hash: ${{ needs.build-context.outputs.config-hash }}
       free-threading: ${{ matrix.free-threading }}
 
+  build-ubsan:
+    name: Undefined behavior sanitizer
+    needs: build-context
+    if: needs.build-context.outputs.run-tests == 'true'
+    uses: ./.github/workflows/reusable-ubsan.yml
+    with:
+      config_hash: ${{ needs.build-context.outputs.config-hash }}
+
   cross-build-linux:
     name: Cross build Linux
     runs-on: ubuntu-latest

.github/workflows/reusable-ubsan.yml

@@ -0,0 +1,74 @@
+name: Reusable Undefined Behavior Sanitizer
+
+on:
+  workflow_call:
+    inputs:
+      config_hash:
+        required: true
+        type: string
+
+env:
+  FORCE_COLOR: 1
+
+jobs:
+  build-ubsan-reusable:
+    name: 'Undefined behavior sanitizer'
+    runs-on: ubuntu-24.04
+    timeout-minutes: 60
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        persist-credentials: false
+    - name: Runner image version
+      run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
+    - name: Restore config.cache
+      uses: actions/cache@v4
+      with:
+        path: config.cache
+        key: ${{ github.job }}-${{ env.IMAGE_OS_VERSION }}-${{ inputs.config_hash }}
+    - name: Install dependencies
+      run: |
+        sudo ./.github/workflows/posix-deps-apt.sh
+        # Install clang-20
+        wget https://apt.llvm.org/llvm.sh
+        chmod +x llvm.sh
+        sudo ./llvm.sh 20
+    - name: UBSAN option setup
+      run: |
+        echo "UBSAN_OPTIONS=halt_on_error=1:abort_on_error=1:print_summary=1:print_stacktrace=1" >> "$GITHUB_ENV"
+        echo "CC=clang" >> "$GITHUB_ENV"
+        echo "CXX=clang++" >> "$GITHUB_ENV"
+    - name: Add ccache to PATH
+      run: |
+        echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
+    - name: Configure ccache action
+      uses: hendrikmuhs/ccache-action@v1.2
+      with:
+        save: ${{ github.event_name == 'push' }}
+        max-size: "200M"
+    - name: Configure CPython
+      run: >-
+        ./configure
+        --config-cache
+        --with-undefined-behavior-sanitizer
+        --with-pydebug
+    - name: Set up UBSAN log after configuration
+      run: |
+        echo "UBSAN_OPTIONS=${UBSAN_OPTIONS}:log_path=${GITHUB_WORKSPACE}/ubsan_log" >> "$GITHUB_ENV"
+    - name: Build CPython
+      run: make -j4
+    - name: Display build info
+      run: make pythoninfo
+    - name: Tests
+      run: ./python -m test -j4
+    - name: Display UBSAN logs
+      if: always()
+      run: find "${GITHUB_WORKSPACE}" -name 'ubsan_log.*' | xargs head -n 1000
+    - name: Archive UBSAN logs
+      if: always()
+      uses: actions/upload-artifact@v4
+      with:
+        name: >-
+          ubsan-logs
+        path: ubsan_log.*
+        if-no-files-found: ignore

Doc/c-api/refcounting.rst

@@ -210,7 +210,7 @@ of Python objects.
 
         Py_SETREF(dst, src);
 
-   That arranges to set *dst* to *src* _before_ releasing the reference
+   That arranges to set *dst* to *src* *before* releasing the reference
    to the old value of *dst*, so that any code triggered as a side-effect
    of *dst* getting torn down no longer believes *dst* points
    to a valid object.

Doc/c-api/type.rst

@@ -282,6 +282,10 @@ Type Objects
    and other places where a method's defining class cannot be passed using the
    :c:type:`PyCMethod` calling convention.
 
+   The returned reference is :term:`borrowed <borrowed reference>` from *type*,
+   and will be valid as long as you hold a reference to *type*.
+   Do not release it with :c:func:`Py_DECREF` or similar.
+
    .. versionadded:: 3.11
 
 .. c:function:: int PyType_GetBaseByToken(PyTypeObject *type, void *token, PyTypeObject **result)

Doc/conf.py

@@ -79,6 +79,10 @@
 rst_epilog = f"""
 .. |python_version_literal| replace:: ``Python {version}``
 .. |python_x_dot_y_literal| replace:: ``python{version}``
+.. |python_x_dot_y_t_literal| replace:: ``python{version}t``
+.. |python_x_dot_y_t_literal_config| replace:: ``python{version}t-config``
+.. |x_dot_y_b2_literal| replace:: ``{version}.0b2``
+.. |applications_python_version_literal| replace:: ``/Applications/Python {version}/``
 .. |usr_local_bin_python_x_dot_y_literal| replace:: ``/usr/local/bin/python{version}``
 
 .. Apparently this how you hack together a formatted link:

Doc/data/refcounts.dat

@@ -2385,6 +2385,10 @@ PyType_GetFlags:PyTypeObject*:type:0:
 PyType_GetName:PyObject*::+1:
 PyType_GetName:PyTypeObject*:type:0:
 
+PyType_GetModuleByDef:PyObject*::0:
+PyType_GetModuleByDef:PyTypeObject*:type:0:
+PyType_GetModuleByDef:PyModuleDef*:def::
+
 PyType_GetQualName:PyObject*::+1:
 PyType_GetQualName:PyTypeObject*:type:0:
 

Doc/howto/free-threading-extensions.rst

@@ -6,8 +6,8 @@
 C API Extension Support for Free Threading
 ******************************************
 
-Starting with the 3.13 release, CPython has experimental support for running
-with the :term:`global interpreter lock` (GIL) disabled in a configuration
+Starting with the 3.13 release, CPython has support for running with
+the :term:`global interpreter lock` (GIL) disabled in a configuration
 called :term:`free threading`.  This document describes how to adapt C API
 extensions to support free threading.
 

Doc/howto/free-threading-python.rst

@@ -1,18 +1,21 @@
 .. _freethreading-python-howto:
 
-**********************************************
-Python experimental support for free threading
-**********************************************
+*********************************
+Python support for free threading
+*********************************
 
-Starting with the 3.13 release, CPython has experimental support for a build of
+Starting with the 3.13 release, CPython has support for a build of
 Python called :term:`free threading` where the :term:`global interpreter lock`
 (GIL) is disabled.  Free-threaded execution allows for full utilization of the
 available processing power by running threads in parallel on available CPU cores.
 While not all software will benefit from this automatically, programs
 designed with threading in mind will run faster on multi-core hardware.
 
-**The free-threaded mode is experimental** and work is ongoing to improve it:
-expect some bugs and a substantial single-threaded performance hit.
+The free-threaded mode is working and continues to be improved, but
+there is some additional overhead in single-threaded workloads compared
+to the regular build. Additionally, third-party packages, in particular ones
+with an :term:`extension module`, may not be ready for use in a
+free-threaded build, and will re-enable the :term:`GIL`.
 
 This document describes the implications of free threading
 for Python code.  See :ref:`freethreading-extensions-howto` for information on
@@ -43,7 +46,7 @@ Identifying free-threaded Python
 ================================
 
 To check if the current interpreter supports free-threading, :option:`python -VV <-V>`
-and :data:`sys.version` contain "experimental free-threading build".
+and :data:`sys.version` contain "free-threading build".
 The new :func:`sys._is_gil_enabled` function can be used to check whether
 the GIL is actually disabled in the running process.
 

Doc/howto/regex.rst

@@ -1016,7 +1016,9 @@ extension.  This regular expression matches ``foo.bar`` and
 Now, consider complicating the problem a bit; what if you want to match
 filenames where the extension is not ``bat``? Some incorrect attempts:
 
-``.*[.][^b].*$``  The first attempt above tries to exclude ``bat`` by requiring
+``.*[.][^b].*$``
+
+The first attempt above tries to exclude ``bat`` by requiring
 that the first character of the extension is not a ``b``.  This is wrong,
 because the pattern also doesn't match ``foo.bar``.
 
@@ -1043,7 +1045,9 @@ confusing.
 
 A negative lookahead cuts through all this confusion:
 
-``.*[.](?!bat$)[^.]*$``  The negative lookahead means: if the expression ``bat``
+``.*[.](?!bat$)[^.]*$``
+
+The negative lookahead means: if the expression ``bat``
 doesn't match at this point, try the rest of the pattern; if ``bat$`` does
 match, the whole pattern will fail.  The trailing ``$`` is required to ensure
 that something like ``sample.batch``, where the extension only starts with