Merge branch 'main' of github.com:python/cpython into defaultdict

Author: LindaSummer

.gitignore

@@ -45,6 +45,7 @@ gmon.out
 .pytest_cache/
 .ruff_cache/
 .DS_Store
+.pixi/
 
 *.exe
 

Doc/library/ctypes.rst

@@ -1388,6 +1388,9 @@ On Linux, :func:`~ctypes.util.find_library` tries to run external programs
 (``/sbin/ldconfig``, ``gcc``, ``objdump`` and ``ld``) to find the library file.
 It returns the filename of the library file.
 
+Note that if the output of these programs does not correspond to the dynamic
+linker used by Python, the result of this function may be misleading.
+
 .. versionchanged:: 3.6
    On Linux, the value of the environment variable ``LD_LIBRARY_PATH`` is used
    when searching for libraries, if a library cannot be found by any other means.
@@ -2132,6 +2135,8 @@ Utility functions
 
    The exact functionality is system dependent.
 
+   See :ref:`ctypes-finding-shared-libraries` for complete documentation.
+
 
 .. function:: find_msvcrt()
    :module: ctypes.util

InternalDocs/README.md

@@ -11,6 +11,11 @@ it is not, please report that through the
 [issue tracker](https://github.com/python/cpython/issues).
 
 
+General Resources
+---
+
+- [Source Code Structure](structure.md)
+
 Compiling Python Source Code
 ---
 

InternalDocs/structure.md

@@ -0,0 +1,40 @@
+# CPython source code
+
+This section gives an overview of CPython's code structure and provides
+a summary of file locations for modules and built-ins.
+
+
+## Source code layout
+
+For a Python module, the typical layout is:
+
+* `Lib/<module>.py`
+* `Modules/_<module>.c` (if there's also a C accelerator module)
+* `Lib/test/test_<module>.py`
+* `Doc/library/<module>.rst`
+
+For an extension module, the typical layout is:
+
+* `Modules/<module>module.c`
+* `Lib/test/test_<module>.py`
+* `Doc/library/<module>.rst`
+
+For builtin types, the typical layout is:
+
+* `Objects/<builtin>object.c`
+* `Lib/test/test_<builtin>.py`
+* [`Doc/library/stdtypes.rst`](../Doc/library/stdtypes.rst)
+
+For builtin functions, the typical layout is:
+
+* [`Python/bltinmodule.c`](../Python/bltinmodule.c)
+* [`Lib/test/test_builtin.py`](../Lib/test/test_builtin.py)
+* [`Doc/library/functions.rst`](../Doc/library/functions.rst)
+
+Some exceptions to these layouts are:
+
+* built-in type `int` is at [`Objects/longobject.c`](../Objects/longobject.c)
+* built-in type `str` is at [`Objects/unicodeobject.c`](../Objects/unicodeobject.c)
+* built-in module `sys` is at [`Python/sysmodule.c`](../Python/sysmodule.c)
+* built-in module `marshal` is at [`Python/marshal.c`](../Python/marshal.c)
+* Windows-only module `winreg` is at [`PC/winreg.c`](../PC/winreg.c)

Lib/test/test_io/test_textio.py

@@ -1544,6 +1544,22 @@ def write(self, data):
         self.assertEqual([b"abcdef", b"middle", b"g"*chunk_size],
                          buf._write_stack)
 
+    def test_issue142594(self):
+        wrapper = None
+        detached = False
+        class ReentrantRawIO(self.RawIOBase):
+            @property
+            def closed(self):
+                nonlocal detached
+                if wrapper is not None and not detached:
+                    detached = True
+                    wrapper.detach()
+                return False
+
+        raw = ReentrantRawIO()
+        wrapper = self.TextIOWrapper(raw)
+        wrapper.close()  # should not crash
+
 
 class PyTextIOWrapperTest(TextIOWrapperTest, PyTestCase):
     shutdown_error = "LookupError: unknown encoding: ascii"

Misc/NEWS.d/next/Library/2025-12-14-18-30-48.gh-issue-142594.belDmD.rst

@@ -0,0 +1,2 @@
+Fix crash in ``TextIOWrapper.close()`` when the underlying buffer's
+``closed`` property calls :meth:`~io.TextIOBase.detach`.

Modules/_io/textio.c

@@ -3150,6 +3150,9 @@ _io_TextIOWrapper_close_impl(textio *self)
     if (r > 0) {
         Py_RETURN_NONE; /* stream already closed */
     }
+    if (self->detached) {
+        Py_RETURN_NONE; /* gh-142594 null pointer issue */
+    }
     else {
         PyObject *exc = NULL;
         if (self->finalizing) {

Tools/README

@@ -43,6 +43,8 @@ patchcheck      Tools for checking and applying patches to the Python source cod
 
 peg_generator   PEG-based parser generator (pegen) used for new parser.
 
+pixi-packages   Pixi package definitions for downstream from-source builds.
+
 scripts         A number of useful single-file programs, e.g. run_tests.py
                 which runs the Python test suite.
 

Tools/pixi-packages/README.md

@@ -0,0 +1,36 @@
+# CPython Pixi packages
+
+This directory contains definitions for [Pixi packages](https://pixi.sh/latest/reference/pixi_manifest/#the-package-section)
+which can be built from the CPython source code.
+
+Downstream developers can make use of these packages by adding them as Git dependencies in a
+[Pixi workspace](https://pixi.sh/latest/first_workspace/), like:
+
+```toml
+[dependencies]
+python = { git = "https://github.com/python/cpython", subdirectory = "Tools/pixi-packages/asan" }
+```
+
+This is particularly useful when developers need to build CPython from source
+(for example, for an ASan-instrumented build), as it does not require any manual
+clone or build steps. Instead, Pixi will automatically handle both the build
+and installation of the package.
+
+Each package definition is contained in a subdirectory, but they share the build script
+`build.sh` in this directory. Currently defined package variants:
+
+- `default`
+- `asan`: ASan-instrumented build with `PYTHON_ASAN=1`
+
+## Maintenance
+
+- Keep the `version` fields in each `recipe.yaml` up to date with the Python version
+- Keep the dependency requirements up to date in each `recipe.yaml`
+- Update `build.sh` for any breaking changes in the `configure` and `make` workflow
+
+## Opportunities for future improvement
+
+- More package variants (such as TSan, UBSan)
+- Support for Windows
+- Using a single `pixi.toml` and `recipe.yaml` for all package variants is blocked on https://github.com/prefix-dev/pixi/issues/4599
+- A workaround can be removed from the build script once https://github.com/prefix-dev/rattler-build/issues/2012 is resolved

Tools/pixi-packages/asan/pixi.toml

@@ -0,0 +1,8 @@
+[workspace]
+channels = ["https://prefix.dev/conda-forge"]
+platforms = ["osx-arm64", "linux-64"]
+preview = ["pixi-build"]
+
+[package.build.backend]
+name = "pixi-build-rattler-build"
+version = "*"