@@ -283,11 +283,10 @@ Programs/_bootstrap_python.c  @ericsnowcurrently @FFY00
 Programs/python.c             @ericsnowcurrently @FFY00
 
 # JIT
-.github/workflows/jit.yml     @savannahostrowski
-Include/internal/pycore_jit.h @brandtbucher @savannahostrowski @diegorusso
-Python/jit.c                  @brandtbucher @savannahostrowski @diegorusso
-Tools/jit/                    @brandtbucher @savannahostrowski @diegorusso
-InternalDocs/jit.md           @brandtbucher @savannahostrowski @diegorusso @AA-Turner
+Include/internal/pycore_jit.h @brandtbucher @diegorusso
+Python/jit.c                  @brandtbucher @diegorusso
+Tools/jit/                    @brandtbucher @diegorusso
+InternalDocs/jit.md           @brandtbucher @diegorusso @AA-Turner
 
 # Lazy imports (PEP 810)
 .github/workflows/reusable-test-lazy-imports-all.yml    @yhg1s @DinoV @pablogsal
@@ -297,9 +296,9 @@ Lib/test/test_lazy_import                               @yhg1s @DinoV @pablogsal
 
 # Micro-op / μop / Tier 2 Optimiser
 Python/optimizer.c            @markshannon @Fidget-Spinner
-Python/optimizer_analysis.c   @markshannon @tomasr8 @Fidget-Spinner @savannahostrowski
-Python/optimizer_bytecodes.c  @markshannon @tomasr8 @Fidget-Spinner @savannahostrowski
-Python/optimizer_symbols.c    @markshannon @tomasr8 @Fidget-Spinner @savannahostrowski
+Python/optimizer_analysis.c   @markshannon @tomasr8 @Fidget-Spinner
+Python/optimizer_bytecodes.c  @markshannon @tomasr8 @Fidget-Spinner
+Python/optimizer_symbols.c    @markshannon @tomasr8 @Fidget-Spinner
 
 # Parser, Lexer, and Grammar
 Grammar/python.gram           @pablogsal @lysnikolaou
 
@@ -491,53 +491,6 @@ jobs:
     if: fromJSON(needs.build-context.outputs.run-tests)
     uses: ./.github/workflows/reusable-test-lazy-imports-all.yml
 
-  build-asan:
-    name: 'Address sanitizer'
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 60
-    needs: build-context
-    if: needs.build-context.outputs.run-ubuntu == 'true'
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-26.04]
-    env:
-      OPENSSL_VER: 3.5.9
-      PYTHONSTRICTEXTENSIONBUILD: 1
-      ASAN_OPTIONS: detect_leaks=0:allocator_may_return_null=1:handle_segv=0
-    steps:
-    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-      with:
-        persist-credentials: false
-    - name: Runner image version
-      run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
-    - name: Register gcc problem matcher
-      run: echo "::add-matcher::.github/problem-matchers/gcc.json"
-    - name: Install dependencies
-      run: sudo ./.github/workflows/posix-deps-apt.sh
-    - name: Configure OpenSSL env vars
-      run: |
-        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> "$GITHUB_ENV"
-        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> "$GITHUB_ENV"
-        echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> "$GITHUB_ENV"
-    - name: 'Restore OpenSSL build'
-      id: cache-openssl
-      uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
-      with:
-        path: ./multissl/openssl/${{ env.OPENSSL_VER }}
-        key: ${{ matrix.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
-    - name: Install OpenSSL
-      if: steps.cache-openssl.outputs.cache-hit != 'true'
-      run: python3 Tools/ssl/multissltests.py --steps=library --base-directory "$MULTISSL_DIR" --openssl "$OPENSSL_VER" --system Linux
-    - name: Configure CPython
-      run: ./configure --config-cache --with-address-sanitizer --without-pymalloc --with-openssl="$OPENSSL_DIR"
-    - name: Build CPython
-      run: make -j4
-    - name: Display build info
-      run: make pythoninfo
-    - name: Tests
-      run: xvfb-run make ci
-
   build-san:
     # ${{ '' } is a hack to nest jobs under the same sidebar category.
     name: Sanitizers${{ '' }}  # zizmor: ignore[obfuscation]
@@ -554,6 +507,9 @@ jobs:
         sanitizer:
         - TSan
         include:
+        - check-name: Address
+          sanitizer: ASan
+          free-threading: false
         - check-name: Undefined behavior
           sanitizer: UBSan
           free-threading: false
@@ -667,7 +623,6 @@ jobs:
     - build-wasi
     - test-hypothesis
     - test-lazy-imports-all
-    - build-asan
     - build-san
     - cross-build-linux
     - cifuzz
@@ -714,7 +669,6 @@ jobs:
             build-ubuntu-installed,
             build-ubuntu-ssltests,
             test-hypothesis,
-            build-asan,
             build-san,
             cross-build-linux,
             '
 
@@ -43,6 +43,15 @@ jobs:
         # please update the versions in `Tools/pixi-packages/variants.yaml` too.
         echo "CC=clang" >> "$GITHUB_ENV"
         echo "CXX=clang++" >> "$GITHUB_ENV"
+    - name: ASan option setup
+      if: inputs.sanitizer == 'ASan'
+      run: |
+        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> "$GITHUB_ENV"
+        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> "$GITHUB_ENV"
+        echo "ASAN_OPTIONS=${SAN_LOG_OPTION} detect_leaks=0 allocator_may_return_null=1 handle_segv=0" >> "$GITHUB_ENV"
+        echo "PYTHONSTRICTEXTENSIONBUILD=1" >> "$GITHUB_ENV"
+      env:
+        SAN_LOG_OPTION: log_path=${{ github.workspace }}/san_log
     - name: TSan option setup
       if: inputs.sanitizer == 'TSan'
       run: |
@@ -88,24 +97,27 @@ jobs:
     - name: Add ccache to PATH
       run: |
         echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
-    - name: 'Restore OpenSSL build (TSan)'
+    - name: 'Restore OpenSSL build'
       id: cache-openssl
-      if: inputs.sanitizer == 'TSan'
+      if: inputs.sanitizer == 'TSan' || inputs.sanitizer == 'ASan'
       uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
       with:
         path: ./multissl/openssl/${{ env.OPENSSL_VER }}
-        key: ${{ env.IMAGE_OS_VERSION }}-multissl-openssl-tsan-${{ env.OPENSSL_VER }}
-    - name: Install OpenSSL (TSan)
+        key: >-
+          ${{ env.IMAGE_OS_VERSION }}-multissl-openssl-${{
+            inputs.sanitizer == 'TSan' && 'tsan-' || ''
+          }}${{ env.OPENSSL_VER }}
+    - name: Install OpenSSL
       if: >-
-        inputs.sanitizer == 'TSan'
+        (inputs.sanitizer == 'TSan' || inputs.sanitizer == 'ASan')
         && steps.cache-openssl.outputs.cache-hit != 'true'
       run: >-
         python3 Tools/ssl/multissltests.py
         --steps=library
         --base-directory="${MULTISSL_DIR}"
         --openssl="${OPENSSL_VER}"
         --system=Linux
-        --tsan
+        ${{ inputs.sanitizer == 'TSan' && '--tsan' || '' }}
     # gh-157958: -O2 instead of the pydebug default -Og to avoid a clang 21
     # compile-time blowup on some interpreter files.
     # (https://github.com/llvm/llvm-project/issues/179695)
@@ -117,14 +129,20 @@ jobs:
         --config-cache
         OPT="-O2 -g"
         ${{
-          inputs.sanitizer == 'TSan'
+          inputs.sanitizer == 'ASan'
+          && '--with-address-sanitizer --without-pymalloc'
+          || inputs.sanitizer == 'TSan'
           && '--with-thread-sanitizer'
           || inputs.sanitizer == 'MSan'
           && '--with-memory-sanitizer'
           || '--with-undefined-behavior-sanitizer --with-strict-overflow'
         }}
         ${{ inputs.sanitizer == 'MSan' && '--with-assertions' || '--with-pydebug' }}
-        ${{ inputs.sanitizer == 'TSan' && '--with-openssl="$OPENSSL_DIR" --with-openssl-rpath=auto' || '' }}
+        ${{
+          (inputs.sanitizer == 'TSan' || inputs.sanitizer == 'ASan')
+          && '--with-openssl="$OPENSSL_DIR" --with-openssl-rpath=auto'
+          || ''
+        }}
         ${{ inputs.free-threading && '--disable-gil' || '' }}
     - name: Build CPython
       run: make -j4
 
@@ -313,16 +313,32 @@ This is typically done using :c:func:`PyModule_Create` and functions like
 Single-phase initialization differs from the :ref:`default <multi-phase-initialization>`
 in the following ways:
 
-* Single-phase modules are, or rather *contain*, “singletons”.
+* Single-phase modules with :c:member:`PyModuleDef.m_size` set to -1 are,
+  or rather *contain*, “singletons”.
 
-  When the module is first initialized, Python saves the contents of
+  When such a module is first initialized, Python saves the contents of
   the module's ``__dict__`` (that is, typically, the module's functions and
   types).
 
   For subsequent imports, Python does not call the initialization function
   again.
   Instead, it creates a new module object with a new ``__dict__``, and copies
   the saved contents to it.
+  Modules are matched to the saved contents by a (*module_name*, *file_name*)
+  tuple where:
+
+  - *module_name* is the module's full dotted name, taken from
+    :py:attr:`ModuleSpec.name <importlib.machinery.ModuleSpec.name>`
+    (or the equivalent argument of the importing function).
+    Note that names that the initialization function uses to create the module
+    (for example, :c:member:`PyModuleDef.m_name`) are not taken into account.
+  - *file_name* is the extension's file name.
+    It is unset for modules not loaded from a file, such as built-ins and
+    modules added with :c:func:`PyImport_CreateModuleFromInitfunc` or
+    :c:func:`PyImport_AppendInittab`.
+
+  As part of the first initialization, Python also adds the module to
+  :data:`sys.modules` under its name.
   For example, given a single-phase module ``_testsinglephase``
   [#testsinglephase]_ that defines a function ``sum`` and an exception class
   ``error``:
@@ -344,6 +360,16 @@ in the following ways:
 
   The exact behavior should be considered a CPython implementation detail.
 
+* For single-phase modules with non-negative :c:member:`PyModuleDef.m_size`,
+  Python may cache a pointer to the initialization function under the
+  (*module_name*, *file_name*) key as for ``m_size == -1``.
+
+  Subsequent imports that specify a different initialization function
+  (for example, using :c:func:`PyImport_CreateModuleFromInitfunc`)
+  may call either the cached function or the provided "new" one.
+
+  The exact behavior should again be considered a CPython implementation detail.
+
 * To work around the fact that ``PyInit_modulename`` does not take a *spec*
   argument, some state of the import machinery is saved and applied to the
   first suitable module created during the ``PyInit_modulename`` call.
 
@@ -60,6 +60,29 @@ the :mod:`io` APIs instead.
    raised if the end of the file is reached immediately.
 
 
+.. c:function:: char* Py_UniversalNewlineFgets(char *buf, int n, FILE *stream, PyObject *fobj)
+
+   Read a line from the C stream *stream* into the buffer *buf*, like the
+   C standard library function :c:func:`!fgets`, but treating all of ``\n``,
+   ``\r`` and ``\r\n`` as line endings (see :term:`universal newlines`).
+   Any ``\r`` or ``\r\n`` read from the stream is stored in *buf* as a
+   single ``\n``.
+
+   At most ``n - 1`` characters are stored in *buf*; reading stops after a
+   newline has been stored or when the end of the file is reached.
+   The result is always null-terminated.
+   *stream* should be opened in binary mode, so that the C library does not
+   perform its own newline translation.
+
+   Return *buf* on success.
+   Return ``NULL`` if no characters could be read, because *stream* is at
+   end of file, a read error occurred, or *n* is less than 2.
+   Like :c:func:`!fgets`, this function does not distinguish between end of
+   file and a read error, and it does not set an exception.
+
+   *fobj* exists only for backward compatibility and must be ``NULL``.
+
+
 .. c:function:: int PyFile_SetOpenCodeHook(Py_OpenCodeHookFunction handler)
 
    Overrides the normal behavior of :func:`io.open_code` to pass its parameter
 
@@ -214,7 +214,7 @@ Pack functions
 The pack routines write 2, 4 or 8 bytes, starting at *p*. *le* is an
 :c:expr:`int` argument, non-zero if you want the bytes string in little-endian
 format (exponent last, at ``p+1``, ``p+3``, or ``p+6`` and ``p+7``), zero if you
-want big-endian format (exponent first, at *p*). Use the :c:macro:`!PY_LITTLE_ENDIAN`
+want big-endian format (exponent first, at *p*). Use the :c:macro:`PY_LITTLE_ENDIAN`
 constant to select the native endian: it is equal to ``0`` on big
 endian processor, or ``1`` on little endian processor.
 
@@ -240,7 +240,7 @@ Unpack functions
 The unpack routines read 2, 4 or 8 bytes, starting at *p*.  *le* is an
 :c:expr:`int` argument, non-zero if the bytes string is in little-endian format
 (exponent last, at ``p+1``, ``p+3`` or ``p+6`` and ``p+7``), zero if big-endian
-(exponent first, at *p*). Use the :c:macro:`!PY_LITTLE_ENDIAN` constant to
+(exponent first, at *p*). Use the :c:macro:`PY_LITTLE_ENDIAN` constant to
 select the native endian: it is equal to ``0`` on big endian processor, or ``1``
 on little endian processor.
 
 
@@ -408,7 +408,7 @@ Importing Modules
 
    *spec* must be a :class:`~importlib.machinery.ModuleSpec` object.
 
-   *initfunc* must be an :ref:`initialization function <extension-export-hook>`,
+   *initfunc* must be an :ref:`initialization function <extension-pyinit>`,
    the same as for :c:func:`PyImport_AppendInittab`.
 
    On success, create and return a module object.
@@ -417,10 +417,27 @@ Importing Modules
    (Custom importers should do this in their
    :py:meth:`~importlib.abc.Loader.exec_module` method.)
 
-   If the spec's name is dotted and *initfunc* creates the module using only
-   the last component of the name, the module's :attr:`~module.__name__`
-   is set to the full name from the spec.
-
    On error, return NULL with an exception set.
 
+   For modules using :ref:`legacy single-phase initialization <single-phase-initialization>`,
+   most of the import process is done in this function, rather than in
+   extra steps that importers typically take after
+   :py:meth:`~importlib.abc.Loader.create_module`.
+   Specifically:
+
+   - The module is added to :data:`sys.modules` under the *spec*'s
+     :py:attr:`~importlib.machinery.ModuleSpec.name` as part of initialization.
+   - If a single-phase module was previously imported under the
+     same :py:attr:`~importlib.machinery.ModuleSpec.name` by this function
+     or as a built-in module (for example, one registered with
+     :c:func:`PyImport_AppendInittab`), Python may reuse the previous module's
+     contents instead of calling *initfunc* again.
+   - The module will be fully initialized by *initfunc*.
+     Calling :c:func:`PyModule_Exec` on it will have no effect, though it is
+     still recommended, in case the module later switches to
+     :ref:`multi-phase initialization <multi-phase-initialization>`.
+   - Also, if the *spec*'s :py:attr:`!name` contains dots, this name is used
+     for prepending a parent package to the new module's
+     :attr:`~module.__name__`.
+
    .. versionadded:: 3.15
@@ -265,6 +265,48 @@ Initializing and finalizing the interpreter
    first initialized).
 
 
+.. c:function:: int Py_FrozenMain(int argc, char **argv)
+
+   .. index:: single: freeze utility
+
+   The main program for a "frozen" Python program (an executable that embeds
+   the interpreter together with the bytecode of the program's modules, as
+   produced by the :program:`freeze` utility; see :source:`Tools/freeze`).
+
+   This function initializes the interpreter, imports the frozen module named
+   ``__main__``, and finalizes the interpreter.
+   The frozen modules must have been registered in
+   :c:var:`PyImport_FrozenModules` before calling this function;
+   it is a fatal error if ``__main__`` is not among them.
+
+   *argc* and *argv* are byte strings like the arguments of a C program's
+   ``main`` function, and are passed to the interpreter with
+   :c:func:`PyConfig_SetBytesArgv`.
+   Unlike :c:func:`Py_Main`, the arguments are not parsed as Python command
+   line options (:c:member:`PyConfig.parse_argv` is ``0``), so all of them
+   are made available to the program in :data:`sys.argv`.
+   Apart from that, the interpreter uses the
+   :ref:`Python Configuration <init-python-config>`, so environment variables
+   such as :envvar:`PYTHONPATH` are honored.
+   Warnings about the path configuration
+   (:c:member:`PyConfig.pathconfig_warnings`) are suppressed.
+   If :envvar:`PYTHONINSPECT` is set and standard input is a terminal, an
+   interactive prompt is run after ``__main__`` has finished, as with the
+   :option:`-i` option.
+
+   Return ``0`` if ``__main__`` ran without an unhandled exception, ``1``
+   otherwise, and ``120`` if finalizing the interpreter failed (see
+   :c:func:`Py_FinalizeEx`).
+   An unhandled :exc:`SystemExit` terminates the process.
+   If the interpreter cannot be initialized, the process exits via
+   :c:func:`Py_ExitStatusException`.
+
+   On Windows, this function is not exported by the Python DLL.
+   The :program:`freeze` utility compiles :file:`Python/frozenmain.c` into the
+   frozen program instead, together with the Windows-specific hooks that the
+   function requires.
+
+
 .. c:function:: int Py_RunMain(void)
 
    Executes the main module in a fully configured CPython runtime.