Merge remote-tracking branch 'upstream/main' into tachyon-ndjson-kolektor

* upstream/main: (119 commits)
  gh-144270: Make SubElement parent and tag positional-only (GH-144845)
  gh-146558: JIT optimize dict access for objects with known hash (#146559)
  gh-139922: always run MSVC 64-bit tail-calling CI (GH-146570)
  gh-126835: Fix _PY_IS_SMALL_INT() macro (#146631)
  gh-146587: fix type slot assignment incase of multiple slots for same name (#146593)
  gh-138122: Add differential flame graph (#145785)
  gh-146416: Emscripten: Improve standard stream handling in node_entry.mjs (#146417)
  gh-146444: Don't package as part of iOS 'build hosts' target (#146628)
  gh-138850: Add --disable-epoll to configure (GH-145768)
  gh-146444: Make Platforms/Apple/ compatible with Python 3.9 (#146624)
  gh-138577: Fix keyboard shortcuts in getpass with echo_char (#141597)
  gh-146556: Fix infinite loop in annotationlib.get_annotations() on circular __wrapped__ (#146557)
  gh-146579: _zstd: Fix decompression options dict error message (#146577)
  gh-146083: Upgrade bundled Expat to 2.7.5 (#146085)
  gh-146080: fix a crash in SNI callbacks when the SSL object is gone (#146573)
  gh-146090: fix memory management of internal `sqlite3` callback contexts (#146569)
  gh-145876: Do not mask KeyErrors raised during dictionary unpacking in call (GH-146472)
  gh-146004: fix test_args_from_interpreter_flags on windows (#146580)
  gh-139003: Use frozenset for module level attributes in _pyrepl.utils (#139004)
  GH-146527: Add more data to GC statistics and add it to PyDebugOffsets (#146532)
  ...

Author: maurycy

.gitattributes

@@ -112,3 +112,4 @@ Tools/peg_generator/pegen/grammar_parser.py         generated
 aclocal.m4                                          generated
 configure                                           generated
 *.min.js                                            generated
+package-lock.json                                   generated

.github/CODEOWNERS

@@ -427,19 +427,19 @@ Lib/dataclasses.py            @ericvsmith
 Lib/test/test_dataclasses/    @ericvsmith
 
 # Dates and times
-Doc/**/*time.rst                 @pganssle @abalkin @StanFromIreland
+Doc/**/*time.rst                 @pganssle @StanFromIreland
 Doc/library/datetime-*           @pganssle @StanFromIreland
 Doc/library/zoneinfo.rst         @pganssle @StanFromIreland
-Include/datetime.h               @pganssle @abalkin @StanFromIreland
-Include/internal/pycore_time.h   @pganssle @abalkin @StanFromIreland
+Include/datetime.h               @pganssle @StanFromIreland
+Include/internal/pycore_time.h   @pganssle @StanFromIreland
 Lib/test/test_zoneinfo/          @pganssle @StanFromIreland
 Lib/zoneinfo/                    @pganssle @StanFromIreland
-Lib/*time.py                     @pganssle @abalkin @StanFromIreland
-Lib/test/datetimetester.py       @pganssle @abalkin @StanFromIreland
-Lib/test/test_*time.py           @pganssle @abalkin @StanFromIreland
+Lib/*time.py                     @pganssle @StanFromIreland
+Lib/test/datetimetester.py       @pganssle @StanFromIreland
+Lib/test/test_*time.py           @pganssle @StanFromIreland
 Modules/*zoneinfo*               @pganssle @StanFromIreland
-Modules/*time*                   @pganssle @abalkin @StanFromIreland
-Python/pytime.c                  @pganssle @abalkin @StanFromIreland
+Modules/*time*                   @pganssle @StanFromIreland
+Python/pytime.c                  @pganssle @StanFromIreland
 
 # Dbm
 Doc/library/dbm.rst           @corona10 @erlend-aasland @serhiy-storchaka

.github/actionlint.yaml

@@ -1,3 +1,8 @@
+self-hosted-runner:
+  # Pending release of actionlint > 1.7.11 for macos-26-intel support
+  # https://github.com/rhysd/actionlint/pull/629
+  labels: ["macos-26-intel"]
+
 config-variables: null
 
 paths:

.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.
@@ -198,16 +206,16 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # macos-14 is M1, macos-15-intel is Intel.
-        # macos-15-intel only runs tests against the GIL-enabled CPython.
+        # macos-26 is Apple Silicon, macos-26-intel is Intel.
+        # macos-26-intel only runs tests against the GIL-enabled CPython.
         os:
-        - macos-14
-        - macos-15-intel
+        - macos-26
+        - macos-26-intel
         free-threading:
         - false
         - true
         exclude:
-        - os: macos-15-intel
+        - os: macos-26-intel
           free-threading: true
     uses: ./.github/workflows/reusable-macos.yml
     with:
@@ -336,7 +344,7 @@ jobs:
       matrix:
         include:
           - arch: aarch64
-            runs-on: macos-14
+            runs-on: macos-26
           - arch: x86_64
             runs-on: ubuntu-24.04
 
@@ -369,7 +377,13 @@ 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'
+    needs: build-context
+    if: needs.build-context.outputs.run-emscripten == 'true'
+    uses: ./.github/workflows/reusable-emscripten.yml
 
   build-wasi:
     name: 'WASI'
@@ -650,6 +664,7 @@ jobs:
     - build-ubuntu
     - build-ubuntu-ssltests
     - build-ios
+    - build-emscripten
     - build-wasi
     - test-hypothesis
     - build-asan
@@ -664,6 +679,7 @@ jobs:
       with:
         allowed-failures: >-
           build-android,
+          build-emscripten,
           build-windows-msi,
           build-ubuntu-ssltests,
           test-hypothesis,
@@ -706,5 +722,6 @@ jobs:
           }}
           ${{ !fromJSON(needs.build-context.outputs.run-android) && 'build-android,' || '' }}
           ${{ !fromJSON(needs.build-context.outputs.run-ios) && 'build-ios,' || '' }}
+          ${{ !fromJSON(needs.build-context.outputs.run-emscripten) && 'build-emscripten,' || '' }}
           ${{ !fromJSON(needs.build-context.outputs.run-wasi) && 'build-wasi,' || '' }}
         jobs: ${{ toJSON(needs) }}

.github/workflows/jit.yml

@@ -99,9 +99,9 @@ jobs:
           - false
         include:
           - target: x86_64-apple-darwin/clang
-            runner: macos-15-intel
+            runner: macos-26-intel
           - target: aarch64-apple-darwin/clang
-            runner: macos-14
+            runner: macos-26
     steps:
       - uses: actions/checkout@v6
         with:

.github/workflows/reusable-context.yml

@@ -41,6 +41,9 @@ on:  # yamllint disable-line rule:truthy
       run-ubuntu:
         description: Whether to run the Ubuntu tests
         value: ${{ jobs.compute-changes.outputs.run-ubuntu }}  # bool
+      run-emscripten:
+        description: Whether to run the Emscripten tests
+        value: ${{ jobs.compute-changes.outputs.run-emscripten }}  # bool
       run-wasi:
         description: Whether to run the WASI tests
         value: ${{ jobs.compute-changes.outputs.run-wasi }}  # bool
@@ -65,6 +68,7 @@ jobs:
       run-macos: ${{ steps.changes.outputs.run-macos }}
       run-tests: ${{ steps.changes.outputs.run-tests }}
       run-ubuntu: ${{ steps.changes.outputs.run-ubuntu }}
+      run-emscripten: ${{ steps.changes.outputs.run-emscripten }}
       run-wasi: ${{ steps.changes.outputs.run-wasi }}
       run-windows-msi: ${{ steps.changes.outputs.run-windows-msi }}
       run-windows-tests: ${{ steps.changes.outputs.run-windows-tests }}

.github/workflows/reusable-emscripten.yml

@@ -0,0 +1,74 @@
+name: Reusable Emscripten
+
+on:
+  workflow_call:
+
+env:
+  FORCE_COLOR: 1
+
+jobs:
+  build-emscripten-reusable:
+    name: 'build and test'
+    runs-on: ubuntu-24.04
+    timeout-minutes: 60
+    steps:
+    - uses: actions/checkout@v6
+      with:
+        persist-credentials: false
+    - name: "Read Emscripten config"
+      id: emscripten-config
+      shell: python
+      run: |
+        import hashlib
+        import json
+        import os
+        import tomllib
+        from pathlib import Path
+
+        config = tomllib.loads(Path("Platforms/emscripten/config.toml").read_text())
+        h = hashlib.sha256()
+        h.update(json.dumps(config["dependencies"], sort_keys=True).encode())
+        h.update(Path("Platforms/emscripten/make_libffi.sh").read_bytes())
+        h.update(b'1') # Update to explicitly bust cache
+        emsdk_cache = Path(os.environ["RUNNER_TEMP"]) / "emsdk-cache"
+        with open(os.environ["GITHUB_OUTPUT"], "a") as f:
+            f.write(f"emscripten-version={config['emscripten-version']}\n")
+            f.write(f"node-version={config['node-version']}\n")
+            f.write(f"deps-hash={h.hexdigest()}\n")
+        with open(os.environ["GITHUB_ENV"], "a") as f:
+            f.write(f"EMSDK_CACHE={emsdk_cache}\n")
+    - name: "Install Node.js"
+      uses: actions/setup-node@v6
+      with:
+        node-version: ${{ steps.emscripten-config.outputs.node-version }}
+    - name: "Cache Emscripten SDK"
+      id: emsdk-cache
+      uses: actions/cache@v5
+      with:
+        path: ${{ env.EMSDK_CACHE }}
+        key: emsdk-${{ steps.emscripten-config.outputs.emscripten-version }}-${{ steps.emscripten-config.outputs.deps-hash }}
+        restore-keys: emsdk-${{ steps.emscripten-config.outputs.emscripten-version }}
+    - name: "Install Python"
+      uses: actions/setup-python@v6
+      with:
+        python-version: '3.x'
+    - name: "Runner image version"
+      run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
+    - name: "Install Emscripten"
+      run: python3 Platforms/emscripten install-emscripten
+    - name: "Configure build Python"
+      run: python3 Platforms/emscripten configure-build-python -- --config-cache --with-pydebug
+    - name: "Make build Python"
+      run: python3 Platforms/emscripten make-build-python
+    - name: "Make dependencies"
+      run: >-
+        python3 Platforms/emscripten make-dependencies
+        ${{ steps.emsdk-cache.outputs.cache-hit == 'true' && '--check-up-to-date' || '' }}
+    - name: "Configure host Python"
+      run: python3 Platforms/emscripten configure-host --host-runner node -- --config-cache
+    - name: "Make host Python"
+      run: python3 Platforms/emscripten make-host
+    - name: "Display build info"
+      run: python3 Platforms/emscripten run --pythoninfo
+    - name: "Test"
+      run: python3 Platforms/emscripten run --test

.github/workflows/reusable-macos.yml

@@ -52,15 +52,15 @@ jobs:
           --prefix=/opt/python-dev \
           --with-openssl="$(brew --prefix openssl@3.5)"
     - name: Build CPython
-      if : ${{ inputs.free-threading || inputs.os != 'macos-15-intel' }}
+      if : ${{ inputs.free-threading || inputs.os != 'macos-26-intel' }}
       run: gmake -j8
     - name: Build CPython for compiler warning check
-      if : ${{ !inputs.free-threading && inputs.os == 'macos-15-intel' }}
+      if : ${{ !inputs.free-threading && inputs.os == 'macos-26-intel' }}
       run: set -o pipefail; gmake -j8 --output-sync 2>&1 | tee compiler_output_macos.txt
     - name: Display build info
       run: make pythoninfo
     - name: Check compiler warnings
-      if : ${{ !inputs.free-threading && inputs.os == 'macos-15-intel' }}
+      if : ${{ !inputs.free-threading && inputs.os == 'macos-26-intel' }}
       run: >-
         python3 Tools/build/check_warnings.py
         --compiler-output-file-path=compiler_output_macos.txt

.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 }}
@@ -67,9 +32,9 @@ jobs:
       matrix:
         include:
           - target: x86_64-apple-darwin/clang
-            runner: macos-15-intel
+            runner: macos-26-intel
           - target: aarch64-apple-darwin/clang
-            runner: macos-14
+            runner: macos-26
     steps:
       - uses: actions/checkout@v6
         with: