Merge branch 'main' into add-gdb-support

Author: diegorusso

.github/workflows/build.yml

@@ -165,13 +165,21 @@ jobs:
         free-threading:
           - false
           - true
+        interpreter:
+          - switch-case
         exclude:
           # Skip Win32 on free-threaded builds
           - { arch: Win32, free-threading: true }
+        include:
+          # msvc::musttail is currently only supported on x64,
+          # and only supported on 3.15+.
+          - { arch: x64, free-threading: false, interpreter: tail-call }
+          - { arch: x64, free-threading: true,  interpreter: tail-call }
     uses: ./.github/workflows/reusable-windows.yml
     with:
       arch: ${{ matrix.arch }}
       free-threading: ${{ matrix.free-threading }}
+      interpreter: ${{ matrix.interpreter }}
 
   build-windows-msi:
     # ${{ '' } is a hack to nest jobs under the same sidebar category.
@@ -369,7 +377,7 @@ jobs:
           sudo xcode-select --switch /Applications/Xcode_15.4.app
 
       - name: Build and test
-        run: python3 Apple ci iOS --fast-ci --simulator 'iPhone SE (3rd generation),OS=17.5'
+        run: python3 Platforms/Apple ci iOS --fast-ci --simulator 'iPhone SE (3rd generation),OS=17.5'
 
   build-emscripten:
     name: 'Emscripten'

.github/workflows/reusable-windows.yml

@@ -12,6 +12,10 @@ on:
         required: false
         type: boolean
         default: false
+      interpreter:
+        description: Which interpreter to build (switch-case or tail-call)
+        required: true
+        type: string
 
 env:
   FORCE_COLOR: 1
@@ -20,7 +24,7 @@ env:
 
 jobs:
   build:
-    name: Build and test (${{ inputs.arch }})
+    name: Build and test (${{ inputs.arch }}, ${{ inputs.interpreter }})
     runs-on: ${{ inputs.arch == 'arm64' && 'windows-11-arm' || 'windows-2025-vs2026' }}
     timeout-minutes: 60
     env:
@@ -33,9 +37,12 @@ jobs:
       if: inputs.arch != 'Win32'
       run: echo "::add-matcher::.github/problem-matchers/msvc.json"
     - name: Build CPython
+      # msvc::musttail is not supported for debug builds, so we have to
+      # switch to release.
       run: >-
         .\\PCbuild\\build.bat
-        -e -d -v
+        -e -v
+        ${{ inputs.interpreter == 'switch-case' && '-d' || '--tail-call-interp -c Release' }}
         -p "${ARCH}"
         ${{ fromJSON(inputs.free-threading) && '--disable-gil' || '' }}
       shell: bash
@@ -45,6 +52,7 @@ jobs:
       run: >-
         .\\PCbuild\\rt.bat
         -p "${ARCH}"
-        -d -q --fast-ci
+        -q --fast-ci
+        ${{ inputs.interpreter == 'switch-case' && '-d' || '' }}
         ${{ fromJSON(inputs.free-threading) && '--disable-gil' || '' }}
       shell: bash

.github/workflows/tail-call.yml

@@ -23,41 +23,6 @@ env:
   LLVM_VERSION: 21
 
 jobs:
-  windows:
-    name: ${{ matrix.target }}
-    runs-on: ${{ matrix.runner }}
-    timeout-minutes: 60
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - target: x86_64-pc-windows-msvc/msvc
-            architecture: x64
-            runner: windows-2025-vs2026
-            build_flags: ""
-            run_tests: true
-          - target: x86_64-pc-windows-msvc/msvc-free-threading
-            architecture: x64
-            runner: windows-2025-vs2026
-            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: Build
-        shell: pwsh
-        run: |
-          ./PCbuild/build.bat --tail-call-interp ${{ matrix.build_flags }} -c Release -p ${{ matrix.architecture }}
-      - name: Test
-        if: matrix.run_tests
-        shell: pwsh
-        run: |
-          ./PCbuild/rt.bat -p ${{ matrix.architecture }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3
-
   macos:
     name: ${{ matrix.target }}
     runs-on: ${{ matrix.runner }}

.pre-commit-config.yaml

@@ -3,9 +3,9 @@ repos:
     rev: a27a2e47c7751b639d2b5badf0ef6ff11fee893f  # frozen: v0.15.4
     hooks:
       - id: ruff-check
-        name: Run Ruff (lint) on Apple/
-        args: [--exit-non-zero-on-fix, --config=Apple/.ruff.toml]
-        files: ^Apple/
+        name: Run Ruff (lint) on Platforms/Apple/
+        args: [--exit-non-zero-on-fix, --config=Platforms/Apple/.ruff.toml]
+        files: ^Platforms/Apple/
       - id: ruff-check
         name: Run Ruff (lint) on Doc/
         args: [--exit-non-zero-on-fix]
@@ -39,9 +39,9 @@ repos:
         args: [--exit-non-zero-on-fix, --config=Tools/wasm/.ruff.toml]
         files: ^Tools/wasm/
       - id: ruff-format
-        name: Run Ruff (format) on Apple/
-        args: [--exit-non-zero-on-fix, --config=Apple/.ruff.toml]
-        files: ^Apple
+        name: Run Ruff (format) on Platforms/Apple/
+        args: [--exit-non-zero-on-fix, --config=Platforms/Apple/.ruff.toml]
+        files: ^Platforms/Apple/
       - id: ruff-format
         name: Run Ruff (format) on Doc/
         args: [--exit-non-zero-on-fix]

Android/android.py

@@ -628,7 +628,8 @@ async def gradle_task(context):
             # Randomization is disabled because order-dependent failures are
             # much less likely to pass on a rerun in single-process mode.
             "-m", "test",
-            f"--{context.ci_mode}-ci", "--single-process", "--no-randomize"
+            f"--{context.ci_mode}-ci", "--single-process", "--no-randomize",
+            "--pythoninfo",
         ]
 
     if not any(arg in context.args for arg in ["-c", "-m"]):

Doc/c-api/bytearray.rst

@@ -44,6 +44,10 @@ Direct API functions
 
    On failure, return ``NULL`` with an exception set.
 
+   .. note::
+      If the object implements the buffer protocol, then the buffer
+      must not be mutated while the bytearray object is being created.
+
 
 .. c:function:: PyObject* PyByteArray_FromStringAndSize(const char *string, Py_ssize_t len)
 
@@ -58,6 +62,10 @@ Direct API functions
 
    On failure, return ``NULL`` with an exception set.
 
+   .. note::
+      If the object implements the buffer protocol, then the buffer
+      must not be mutated while the bytearray object is being created.
+
 
 .. c:function:: Py_ssize_t PyByteArray_Size(PyObject *bytearray)
 
@@ -70,6 +78,9 @@ Direct API functions
    ``NULL`` pointer.  The returned array always has an extra
    null byte appended.
 
+   .. note::
+      It is not thread-safe to mutate the bytearray object while using the returned char array.
+
 
 .. c:function:: int PyByteArray_Resize(PyObject *bytearray, Py_ssize_t len)
 
@@ -89,6 +100,9 @@ These macros trade safety for speed and they don't check pointers.
 
    Similar to :c:func:`PyByteArray_AsString`, but without error checking.
 
+   .. note::
+      It is not thread-safe to mutate the bytearray object while using the returned char array.
+
 
 .. c:function:: Py_ssize_t PyByteArray_GET_SIZE(PyObject *bytearray)
 

Doc/c-api/bytes.rst

@@ -127,6 +127,10 @@ called with a non-bytes parameter.
    Return the bytes representation of object *o* that implements the buffer
    protocol.
 
+   .. note::
+      If the object implements the buffer protocol, then the buffer
+      must not be mutated while the bytes object is being created.
+
 
 .. c:function:: Py_ssize_t PyBytes_Size(PyObject *o)
 
@@ -185,13 +189,20 @@ called with a non-bytes parameter.
    created, the old reference to *bytes* will still be discarded and the value
    of *\*bytes* will be set to ``NULL``; the appropriate exception will be set.
 
+   .. note::
+      If *newpart* implements the buffer protocol, then the buffer
+      must not be mutated while the new bytes object is being created.
 
 .. c:function:: void PyBytes_ConcatAndDel(PyObject **bytes, PyObject *newpart)
 
    Create a new bytes object in *\*bytes* containing the contents of *newpart*
    appended to *bytes*.  This version releases the :term:`strong reference`
    to *newpart* (i.e. decrements its reference count).
 
+   .. note::
+      If *newpart* implements the buffer protocol, then the buffer
+      must not be mutated while the new bytes object is being created.
+
 
 .. c:function:: PyObject* PyBytes_Join(PyObject *sep, PyObject *iterable)
 
@@ -210,6 +221,9 @@ called with a non-bytes parameter.
 
    .. versionadded:: 3.14
 
+   .. note::
+      If *iterable* objects implement the buffer protocol, then the buffers
+      must not be mutated while the new bytes object is being created.
 
 .. c:function:: int _PyBytes_Resize(PyObject **bytes, Py_ssize_t newsize)
 

Doc/conf.py

@@ -177,6 +177,7 @@
     ('c:type', '__int64'),
     ('c:type', 'unsigned __int64'),
     ('c:type', 'double'),
+    ('c:type', '_Float16'),
     # Standard C structures
     ('c:struct', 'in6_addr'),
     ('c:struct', 'in_addr'),

Doc/data/threadsafety.dat

@@ -66,10 +66,61 @@ PyList_Reverse:shared:
 # is a list
 PyList_SetSlice:shared:
 
-# Sort - per-object lock held; comparison callbacks may execute
-# arbitrary Python code
+# Sort - per-object lock held; the list is emptied before sorting
+# so other threads may observe an empty list, but they won't see the
+# intermediate states of the sort
 PyList_Sort:shared:
 
 # Extend - lock target list; also lock source when it is a
 # list, set, or dict
 PyList_Extend:shared:
+
+# Creation - pure allocation, no shared state
+PyBytes_FromString:atomic:
+PyBytes_FromStringAndSize:atomic:
+PyBytes_DecodeEscape:atomic:
+
+# Creation from formatting C primitives - pure allocation, no shared state
+PyBytes_FromFormat:atomic:
+PyBytes_FromFormatV:atomic:
+
+# Creation from object - uses buffer protocol so may call arbitrary code;
+# safe as long as the buffer is not mutated by another thread during the operation
+PyBytes_FromObject:shared:
+
+# Size - uses atomic load on free-threaded builds
+PyBytes_Size:atomic:
+PyBytes_GET_SIZE:atomic:
+
+# Raw data - no locking; mutating it is unsafe if the bytes object is shared between threads
+PyBytes_AsString:compatible:
+PyBytes_AS_STRING:compatible:
+PyBytes_AsStringAndSize:compatible:
+
+# Concatenation - uses buffer protocol; safe as long as buffer is not mutated by another thread during the operation
+PyBytes_Concat:shared:
+PyBytes_ConcatAndDel:shared:
+PyBytes_Join:shared:
+
+# Resizing - safe if the object is unique
+_PyBytes_Resize:distinct:
+
+# Repr - atomic as bytes are immutable
+PyBytes_Repr:atomic:
+
+# Creation from object - may call arbitrary code
+PyByteArray_FromObject:shared:
+
+# Creation - pure allocation, no shared state
+PyByteArray_FromStringAndSize:atomic:
+
+# Concatenation - uses buffer protocol; safe as long as buffer is not mutated by another thread during the operation
+PyByteArray_Concat:shared:
+
+# Size - uses atomic load on free-threaded builds
+PyByteArray_Size:atomic:
+PyByteArray_GET_SIZE:atomic:
+
+# Raw data - no locking; mutating it is unsafe if the bytearray object is shared between threads
+PyByteArray_AsString:compatible:
+PyByteArray_AS_STRING:compatible: