Merge branch 'main' into doc-ob-mutex-warning

Author: overlorde

.github/workflows/tail-call.yml

@@ -1,19 +1,14 @@
 name: Tail calling interpreter
 on:
   pull_request:
-    paths:
+    paths: &paths
       - '.github/workflows/tail-call.yml'
       - 'Python/bytecodes.c'
       - 'Python/ceval.c'
       - 'Python/ceval_macros.h'
       - 'Python/generated_cases.c.h'
   push:
-    paths:
-      - '.github/workflows/tail-call.yml'
-      - 'Python/bytecodes.c'
-      - 'Python/ceval.c'
-      - 'Python/ceval_macros.h'
-      - 'Python/generated_cases.c.h'
+    paths: *paths
   workflow_dispatch:
 
 permissions:
@@ -25,117 +20,109 @@ concurrency:
 
 env:
   FORCE_COLOR: 1
+  LLVM_VERSION: 21
 
 jobs:
-  tail-call:
+  windows:
     name: ${{ matrix.target }}
     runs-on: ${{ matrix.runner }}
-    timeout-minutes: 90
+    timeout-minutes: 60
     strategy:
       fail-fast: false
       matrix:
-        target:
-# Un-comment as we add support for more platforms for tail-calling interpreters.
-#          - i686-pc-windows-msvc/msvc
-          - x86_64-pc-windows-msvc/msvc
-          - free-threading-msvc
-#          - aarch64-pc-windows-msvc/msvc
-          - x86_64-apple-darwin/clang
-          - aarch64-apple-darwin/clang
-          - x86_64-unknown-linux-gnu/gcc
-          - aarch64-unknown-linux-gnu/gcc
-          - free-threading
-        llvm:
-          - 20
         include:
-#          - target: i686-pc-windows-msvc/msvc
-#            architecture: Win32
-#            runner: windows-2022
           - target: x86_64-pc-windows-msvc/msvc
             architecture: x64
             runner: windows-2025-vs2026
-          - target: free-threading-msvc
+            build_flags: ""
+            run_tests: true
+          - target: x86_64-pc-windows-msvc/msvc-free-threading
             architecture: x64
             runner: windows-2025-vs2026
-#          - target: aarch64-pc-windows-msvc/msvc
-#            architecture: ARM64
-#            runner: windows-2022
-          - target: x86_64-apple-darwin/clang
-            architecture: x86_64
-            runner: macos-15-intel
-          - target: aarch64-apple-darwin/clang
-            architecture: aarch64
-            runner: macos-14
-          - target: x86_64-unknown-linux-gnu/gcc
-            architecture: x86_64
-            runner: ubuntu-24.04
-          - target: aarch64-unknown-linux-gnu/gcc
-            architecture: aarch64
-            runner: ubuntu-24.04-arm
-          - target: free-threading
-            architecture: x86_64
-            runner: ubuntu-24.04
+            build_flags: --disable-gil
+            run_tests: false
     steps:
       - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: actions/setup-python@v6
         with:
           python-version: '3.11'
-
-      - name: Native Windows MSVC (release)
-        if: runner.os == 'Windows' && matrix.architecture != 'ARM64' && matrix.target != 'free-threading-msvc'
+      - name: Build
         shell: pwsh
         run: |
           $env:PlatformToolset = "v145"
-          ./PCbuild/build.bat --tail-call-interp -c Release -p ${{ matrix.architecture }}
-          ./PCbuild/rt.bat -p ${{ matrix.architecture }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3
-
-        # No tests:
-      - name: Native Windows MSVC with free-threading (release)
-        if: matrix.target == 'free-threading-msvc'
-        shell: pwsh
-        run: |
-          $env:PlatformToolset = "v145"
-          ./PCbuild/build.bat --tail-call-interp --disable-gil -c Release -p ${{ matrix.architecture }}
-
-      # No tests (yet):
-      - name: Emulated Windows Clang (release)
-        if: runner.os == 'Windows' && matrix.architecture == 'ARM64'
+          ./PCbuild/build.bat --tail-call-interp ${{ matrix.build_flags }} -c Release -p ${{ matrix.architecture }}
+      - name: Test
+        if: matrix.run_tests
         shell: pwsh
         run: |
-          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.0
-          $env:PlatformToolset = "clangcl"
-          $env:LLVMToolsVersion = "${{ matrix.llvm }}.1.0"
-          $env:LLVMInstallDir = "C:\Program Files\LLVM"
-          ./PCbuild/build.bat --tail-call-interp -p ${{ matrix.architecture }}
+          ./PCbuild/rt.bat -p ${{ matrix.architecture }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 
-      - name: Native macOS (release)
-        if: runner.os == 'macOS'
+  macos:
+    name: ${{ matrix.target }}
+    runs-on: ${{ matrix.runner }}
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - target: x86_64-apple-darwin/clang
+            runner: macos-15-intel
+          - target: aarch64-apple-darwin/clang
+            runner: macos-14
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+      - uses: actions/setup-python@v6
+        with:
+          python-version: '3.11'
+      - name: Install dependencies
         run: |
           brew update
-          brew install llvm@${{ matrix.llvm }}
+          brew install llvm@${{ env.LLVM_VERSION }}
+      - name: Build
+        run: |
           export SDKROOT="$(xcrun --show-sdk-path)"
-          export PATH="/usr/local/opt/llvm@${{ matrix.llvm }}/bin:$PATH"
-          export PATH="/opt/homebrew/opt/llvm@${{ matrix.llvm }}/bin:$PATH"
-          CC=clang-20 ./configure --with-tail-call-interp
+          export PATH="/usr/local/opt/llvm@${{ env.LLVM_VERSION }}/bin:$PATH"
+          export PATH="/opt/homebrew/opt/llvm@${{ env.LLVM_VERSION }}/bin:$PATH"
+          CC=clang-${{ env.LLVM_VERSION }} ./configure --with-tail-call-interp
           make all --jobs 4
+      - name: Test
+        run: |
           ./python.exe -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 
-      - name: Native Linux (debug)
-        if: runner.os == 'Linux' && matrix.target != 'free-threading'
+  linux:
+    name: ${{ matrix.target }}
+    runs-on: ${{ matrix.runner }}
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - target: x86_64-unknown-linux-gnu/gcc
+            runner: ubuntu-24.04
+            configure_flags: --with-pydebug
+          - target: x86_64-unknown-linux-gnu/gcc-free-threading
+            runner: ubuntu-24.04
+            configure_flags: --disable-gil
+          - target: aarch64-unknown-linux-gnu/gcc
+            runner: ubuntu-24.04-arm
+            configure_flags: --with-pydebug
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+      - uses: actions/setup-python@v6
+        with:
+          python-version: '3.11'
+      - name: Build
         run: |
-          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
-          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
-          CC=clang-20 ./configure --with-tail-call-interp --with-pydebug
+          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM_VERSION }}
+          export PATH="$(llvm-config-${{ env.LLVM_VERSION }} --bindir):$PATH"
+          CC=clang-${{ env.LLVM_VERSION }} ./configure --with-tail-call-interp ${{ matrix.configure_flags }}
           make all --jobs 4
-          ./python -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3
-
-      - name: Native Linux with free-threading (release)
-        if: matrix.target == 'free-threading'
+      - name: Test
         run: |
-          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
-          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
-          CC=clang-20 ./configure --with-tail-call-interp --disable-gil
-          make all --jobs 4
           ./python -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3

Doc/c-api/module.rst

@@ -725,10 +725,11 @@ remove it.
 
       An array of additional slots, terminated by a ``{0, NULL}`` entry.
 
-      This array may not contain slots corresponding to :c:type:`PyModuleDef`
-      members.
-      For example, you cannot use :c:macro:`Py_mod_name` in :c:member:`!m_slots`;
-      the module name must be given as :c:member:`PyModuleDef.m_name`.
+      If the array contains slots corresponding to :c:type:`PyModuleDef`
+      members, the values must match.
+      For example, if you use :c:macro:`Py_mod_name` in :c:member:`!m_slots`,
+      :c:member:`PyModuleDef.m_name` must be set to the same pointer
+      (not just an equal string).
 
       .. versionchanged:: 3.5
 

Doc/deprecations/pending-removal-in-future.rst

@@ -35,7 +35,6 @@ although there is currently no date scheduled for their removal.
   * Support for ``__complex__()`` method returning a strict subclass of
     :class:`complex`: these methods will be required to return an instance of
     :class:`complex`.
-  * Delegation of ``int()`` to ``__trunc__()`` method.
   * Passing a complex number as the *real* or *imag* argument in the
     :func:`complex` constructor is now deprecated; it should only be passed
     as a single positional argument.

Doc/library/datetime.rst

@@ -2540,7 +2540,7 @@ requires, and these work on all supported platforms.
 |  ``%e``   | The day of the month as a      | ␣1, ␣2, ..., 31        |       |
 |           | space-padded decimal number.   |                        |       |
 +-----------+--------------------------------+------------------------+-------+
-|  ``%F``   | Equivalent to ``%Y-%m-%d``,    | 2025-10-11,            | \(0)  |
+|  ``%F``   | Equivalent to ``%Y-%m-%d``,    | 2025-10-11,            |       |
 |           | the ISO 8601 format.           | 1001-12-30             |       |
 +-----------+--------------------------------+------------------------+-------+
 |  ``%g``   | Last 2 digits of ISO 8601 year | 00, 01, ..., 99        | \(0)  |
@@ -2673,10 +2673,10 @@ differences between platforms in handling of unsupported format specifiers.
    ``%G``, ``%u`` and ``%V`` were added.
 
 .. versionadded:: 3.12
-   ``%:z`` was added for :meth:`~.datetime.strftime`
+   ``%:z`` was added for :meth:`~.datetime.strftime`.
 
 .. versionadded:: 3.15
-   ``%:z`` was added for :meth:`~.datetime.strptime`
+   ``%:z`` and ``%F`` were added for :meth:`~.datetime.strptime`.
 
 Technical Detail
 ^^^^^^^^^^^^^^^^

Doc/library/typing.rst

@@ -2527,6 +2527,12 @@ types.
 
    .. versionadded:: 3.8
 
+   .. deprecated-removed:: 3.15 3.20
+      It is deprecated to call :func:`isinstance` and :func:`issubclass` checks on
+      protocol classes that were not explicitly decorated with :func:`!runtime_checkable`
+      but that inherit from a runtime-checkable protocol class. This will throw
+      a :exc:`TypeError` in Python 3.20.
+
 .. decorator:: runtime_checkable
 
    Mark a protocol class as a runtime protocol.
@@ -2548,6 +2554,18 @@ types.
       import threading
       assert isinstance(threading.Thread(name='Bob'), Named)
 
+   Runtime checkability of protocols is not inherited. A subclass of a runtime-checkable protocol
+   is only runtime-checkable if it is explicitly marked as such, regardless of class hierarchy::
+
+      @runtime_checkable
+      class Iterable(Protocol):
+          def __iter__(self): ...
+
+      # Without @runtime_checkable, Reversible would no longer be runtime-checkable.
+      @runtime_checkable
+      class Reversible(Iterable, Protocol):
+          def __reversed__(self): ...
+
    This decorator raises :exc:`TypeError` when applied to a non-protocol class.
 
    .. note::
@@ -2588,6 +2606,11 @@ types.
       protocol. See :ref:`What's new in Python 3.12 <whatsnew-typing-py312>`
       for more details.
 
+   .. deprecated-removed:: 3.15 3.20
+      It is deprecated to call :func:`isinstance` and :func:`issubclass` checks on
+      protocol classes that were not explicitly decorated with :func:`!runtime_checkable`
+      but that inherit from a runtime-checkable protocol class. This will throw
+      a :exc:`TypeError` in Python 3.20.
 
 .. class:: TypedDict(dict)
 

Include/datetime.h

@@ -196,8 +196,23 @@ typedef struct {
 /* Define global variable for the C API and a macro for setting it. */
 static PyDateTime_CAPI *PyDateTimeAPI = NULL;
 
-#define PyDateTime_IMPORT \
-    PyDateTimeAPI = (PyDateTime_CAPI *)PyCapsule_Import(PyDateTime_CAPSULE_NAME, 0)
+static inline PyDateTime_CAPI *
+_PyDateTime_IMPORT(void) {
+    PyDateTime_CAPI *val = _Py_atomic_load_ptr(&PyDateTimeAPI);
+    if (val == NULL) {
+        PyDateTime_CAPI *capi = (PyDateTime_CAPI *)PyCapsule_Import(
+            PyDateTime_CAPSULE_NAME, 0);
+        if (capi != NULL) {
+            /* if the compare exchange fails then in that case
+               another thread would have initialized it */
+            _Py_atomic_compare_exchange_ptr(&PyDateTimeAPI, &val, (void *)capi);
+            return capi;
+        }
+    }
+    return val;
+}
+
+#define PyDateTime_IMPORT _PyDateTime_IMPORT()
 
 /* Macro for access to the UTC singleton */
 #define PyDateTime_TimeZone_UTC PyDateTimeAPI->TimeZone_UTC

Lib/_strptime.py

@@ -418,6 +418,7 @@ def __init__(self, locale_time=None):
         mapping['W'] = mapping['U'].replace('U', 'W')
 
         base.__init__(mapping)
+        base.__setitem__('F', self.pattern('%Y-%m-%d'))
         base.__setitem__('T', self.pattern('%H:%M:%S'))
         base.__setitem__('R', self.pattern('%H:%M'))
         base.__setitem__('r', self.pattern(self.locale_time.LC_time_ampm))

Lib/compileall.py

@@ -165,6 +165,14 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=0,
     stripdir = os.fspath(stripdir) if stripdir is not None else None
     name = os.path.basename(fullname)
 
+    # Without a cache_tag, we can only create legacy .pyc files. None of our
+    # callers seem to expect this, so the best we can do is fail without raising
+    if not legacy and sys.implementation.cache_tag is None:
+        if not quiet:
+            print("No cache tag is available to generate .pyc path for",
+                  repr(fullname))
+        return False
+
     dfile = None
 
     if ddir is not None:

Lib/ensurepip/__init__.py

@@ -177,6 +177,8 @@ def _bootstrap(*, root=None, upgrade=False, user=False,
             args += ["--user"]
         if verbosity:
             args += ["-" + "v" * verbosity]
+        if sys.implementation.cache_tag is None:
+            args += ["--no-compile"]
 
         return _run_pip([*args, "pip"], [os.fsdecode(tmp_wheel_path)])
 

Lib/py_compile.py

@@ -194,8 +194,10 @@ def main():
     else:
         filenames = args.filenames
     for filename in filenames:
+        cfilename = (None if sys.implementation.cache_tag
+                     else f"{filename.rpartition('.')[0]}.pyc")
         try:
-            compile(filename, doraise=True)
+            compile(filename, cfilename, doraise=True)
         except PyCompileError as error:
             if args.quiet:
                 parser.exit(1)