Merge branch 'main' into 709funconly

* main: (26 commits)
  pythonGH-101520: Move tracemalloc functionality into core, leaving interface in Modules. (python#104508)
  typing: Add more tests for TypeVar (python#104571)
  pythongh-104572: Improve error messages for invalid constructs in PEP 695 contexts (python#104573)
  typing: Use PEP 695 syntax in typing.py (python#104553)
  pythongh-102153: Start stripping C0 control and space chars in `urlsplit` (python#102508)
  pythongh-104469: Update README.txt for _testcapi (pythongh-104529)
  pythonGH-103092: isolate `_elementtree` (python#104561)
  pythongh-104050: Add typing to Argument Clinic converters (python#104547)
  pythonGH-103906: Remove immortal refcounting in the interpreter (pythonGH-103909)
  pythongh-87474: Fix file descriptor leaks in subprocess.Popen (python#96351)
  pythonGH-103092: isolate `pyexpat`  (python#104506)
  pythongh-75367: Fix data descriptor detection in inspect.getattr_static (python#104517)
  pythongh-104050: Add more annotations to `Tools/clinic.py` (python#104544)
  pythongh-104555: Fix isinstance() and issubclass() for runtime-checkable protocols that use PEP 695 (python#104556)
  pythongh-103865: add monitoring support to LOAD_SUPER_ATTR (python#103866)
  CODEOWNERS: Assign new PEP 695 files to myself (python#104551)
  pythonGH-104510: Fix refleaks in `_io` base types (python#104516)
  pythongh-104539: Fix indentation error in logging.config.rst (python#104545)
  pythongh-104050: Don't star-import 'types' in Argument Clinic (python#104543)
  pythongh-104050: Add basic typing to CConverter in clinic.py (python#104538)
  ...

.github/CODEOWNERS

@@ -22,6 +22,7 @@ configure*                    @erlend-aasland @corona10
 **/*hamt*                     @1st1
 Objects/set*                  @rhettinger
 Objects/dict*                 @methane @markshannon
+Objects/typevarobject.c       @JelleZijlstra
 Objects/type*                 @markshannon
 Objects/codeobject.c          @markshannon
 Objects/frameobject.c         @markshannon
@@ -33,6 +34,7 @@ Python/flowgraph.c            @markshannon @iritkatriel
 Python/ast_opt.c              @isidentical
 Lib/test/test_patma.py        @brandtbucher
 Lib/test/test_peepholer.py    @brandtbucher
+Lib/test/test_type_*.py       @JelleZijlstra
 
 # Exceptions
 Lib/traceback.py              @iritkatriel

Doc/library/ast.rst

@@ -1724,6 +1724,7 @@ Function and class definitions
             body=[
                 FunctionDef(
                     name='f',
+                    typeparams=[],
                     args=arguments(
                         posonlyargs=[],
                         args=[
@@ -1847,6 +1848,7 @@ Function and class definitions
             body=[
                 ClassDef(
                     name='Foo',
+                    typeparams=[],
                     bases=[
                         Name(id='base1', ctx=Load()),
                         Name(id='base2', ctx=Load())],
@@ -1885,6 +1887,7 @@ Async and await
         body=[
             AsyncFunctionDef(
                 name='f',
+                typeparams=[],
                 args=arguments(
                     posonlyargs=[],
                     args=[],

Doc/library/http.client.rst

@@ -394,6 +394,17 @@ HTTPConnection Objects
       one will be automatically generated and transmitted if not provided in
       the headers argument.
 
+
+.. method:: HTTPConnection.get_proxy_response_headers()
+
+   Returns a dictionary with the headers of the response received from
+   the proxy server to the CONNECT request.
+
+   If the CONNECT request was not sent, the method returns an empty dictionary.
+
+   .. versionadded:: 3.12
+
+
 .. method:: HTTPConnection.connect()
 
    Connect to the server specified when the object was created.  By default,

Doc/library/logging.config.rst

@@ -111,7 +111,7 @@ in :mod:`logging` itself) and defining handlers which are declared either in
                                     they or their ancestors are explicitly named
                                     in the logging configuration.
 
-    :param encoding: The encoding used to open file when *fname* is filename.
+   :param encoding: The encoding used to open file when *fname* is filename.
 
    .. versionchanged:: 3.4
       An instance of a subclass of :class:`~configparser.RawConfigParser` is

Doc/library/urllib.parse.rst

@@ -159,6 +159,10 @@ or on combining URL components into a URL string.
       ParseResult(scheme='http', netloc='www.cwi.nl:80', path='/%7Eguido/Python.html',
                   params='', query='', fragment='')
 
+   .. warning::
+
+      :func:`urlparse` does not perform validation.  See :ref:`URL parsing
+      security <url-parsing-security>` for details.
 
    .. versionchanged:: 3.2
       Added IPv6 URL parsing capabilities.
@@ -324,8 +328,14 @@ or on combining URL components into a URL string.
    ``#``, ``@``, or ``:`` will raise a :exc:`ValueError`. If the URL is
    decomposed before parsing, no error will be raised.
 
-   Following the `WHATWG spec`_ that updates RFC 3986, ASCII newline
-   ``\n``, ``\r`` and tab ``\t`` characters are stripped from the URL.
+   Following some of the `WHATWG spec`_ that updates RFC 3986, leading C0
+   control and space characters are stripped from the URL. ``\n``,
+   ``\r`` and tab ``\t`` characters are removed from the URL at any position.
+
+   .. warning::
+
+      :func:`urlsplit` does not perform validation.  See :ref:`URL parsing
+      security <url-parsing-security>` for details.
 
    .. versionchanged:: 3.6
       Out-of-range port numbers now raise :exc:`ValueError`, instead of
@@ -338,6 +348,9 @@ or on combining URL components into a URL string.
    .. versionchanged:: 3.10
       ASCII newline and tab characters are stripped from the URL.
 
+   .. versionchanged:: 3.12
+      Leading WHATWG C0 control and space characters are stripped from the URL.
+
 .. _WHATWG spec: https://url.spec.whatwg.org/#concept-basic-url-parser
 
 .. function:: urlunsplit(parts)
@@ -414,6 +427,35 @@ or on combining URL components into a URL string.
    or ``scheme://host/path``). If *url* is not a wrapped URL, it is returned
    without changes.
 
+.. _url-parsing-security:
+
+URL parsing security
+--------------------
+
+The :func:`urlsplit` and :func:`urlparse` APIs do not perform **validation** of
+inputs.  They may not raise errors on inputs that other applications consider
+invalid.  They may also succeed on some inputs that might not be considered
+URLs elsewhere.  Their purpose is for practical functionality rather than
+purity.
+
+Instead of raising an exception on unusual input, they may instead return some
+component parts as empty strings. Or components may contain more than perhaps
+they should.
+
+We recommend that users of these APIs where the values may be used anywhere
+with security implications code defensively. Do some verification within your
+code before trusting a returned component part.  Does that ``scheme`` make
+sense?  Is that a sensible ``path``?  Is there anything strange about that
+``hostname``?  etc.
+
+What constitutes a URL is not universally well defined.  Different applications
+have different needs and desired constraints.  For instance the living `WHATWG
+spec`_ describes what user facing web clients such as a web browser require.
+While :rfc:`3986` is more general.  These functions incorporate some aspects of
+both, but cannot be claimed compliant with either.  The APIs and existing user
+code with expectations on specific behaviors predate both standards leading us
+to be very cautious about making API behavior changes.
+
 .. _parsing-ascii-encoded-bytes:
 
 Parsing ASCII Encoded Bytes

Grammar/python.gram

@@ -112,6 +112,7 @@ simple_stmts[asdl_stmt_seq*]:
 # will throw a SyntaxError.
 simple_stmt[stmt_ty] (memo):
     | assignment
+    | &"type" type_alias
     | e=star_expressions { _PyAST_Expr(e, EXTRA) }
     | &'return' return_stmt
     | &('import' | 'from') import_stmt
@@ -252,8 +253,8 @@ class_def[stmt_ty]:
 
 class_def_raw[stmt_ty]:
     | invalid_class_def_raw
-    | 'class' a=NAME b=['(' z=[arguments] ')' { z }] ':' c=block {
-        _PyAST_ClassDef(a->v.Name.id,
+    | 'class' a=NAME t=[type_params] b=['(' z=[arguments] ')' { z }] ':' c=block {
+        _PyAST_ClassDef(a->v.Name.id, t,
                      (b) ? ((expr_ty) b)->v.Call.args : NULL,
                      (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
                      c, NULL, EXTRA) }
@@ -267,16 +268,16 @@ function_def[stmt_ty]:
 
 function_def_raw[stmt_ty]:
     | invalid_def_raw
-    | 'def' n=NAME &&'(' params=[params] ')' a=['->' z=expression { z }] &&':' tc=[func_type_comment] b=block {
-        _PyAST_FunctionDef(n->v.Name.id,
+    | 'def' n=NAME t=[type_params] &&'(' params=[params] ')' a=['->' z=expression { z }] &&':' tc=[func_type_comment] b=block {
+        _PyAST_FunctionDef(n->v.Name.id, t,
                         (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
                         b, NULL, a, NEW_TYPE_COMMENT(p, tc), EXTRA) }
-    | ASYNC 'def' n=NAME &&'(' params=[params] ')' a=['->' z=expression { z }] &&':' tc=[func_type_comment] b=block {
+    | ASYNC 'def' n=NAME t=[type_params] &&'(' params=[params] ')' a=['->' z=expression { z }] &&':' tc=[func_type_comment] b=block {
         CHECK_VERSION(
             stmt_ty,
             5,
             "Async functions are",
-            _PyAST_AsyncFunctionDef(n->v.Name.id,
+            _PyAST_AsyncFunctionDef(n->v.Name.id, t,
                             (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
                             b, NULL, a, NEW_TYPE_COMMENT(p, tc), EXTRA)
         ) }
@@ -628,6 +629,39 @@ keyword_patterns[asdl_seq*]:
 keyword_pattern[KeyPatternPair*]:
     | arg=NAME '=' value=pattern { _PyPegen_key_pattern_pair(p, arg, value) }
 
+# Type statement
+# ---------------
+
+type_alias[stmt_ty]:
+    | "type" n=NAME t=[type_params] '=' b=expression {
+        CHECK_VERSION(stmt_ty, 12, "Type statement is",
+        _PyAST_TypeAlias(CHECK(expr_ty, _PyPegen_set_expr_context(p, n, Store)), t, b, EXTRA)) }
+
+# Type parameter declaration
+# --------------------------
+
+type_params[asdl_typeparam_seq*]: '[' t=type_param_seq  ']' {
+        CHECK_VERSION(asdl_typeparam_seq *, 12, "Type parameter lists are", t) }
+
+type_param_seq[asdl_typeparam_seq*]: a[asdl_typeparam_seq*]=','.type_param+ [','] { a }
+
+type_param[typeparam_ty] (memo):
+    | a=NAME b=[type_param_bound] { _PyAST_TypeVar(a->v.Name.id, b, EXTRA) }
+    | '*' a=NAME colon=":" e=expression {
+            RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
+                ? "cannot use constraints with TypeVarTuple"
+                : "cannot use bound with TypeVarTuple")
+        }
+    | '*' a=NAME { _PyAST_TypeVarTuple(a->v.Name.id, EXTRA) }
+    | '**' a=NAME colon=":" e=expression {
+            RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
+                ? "cannot use constraints with ParamSpec"
+                : "cannot use bound with ParamSpec")
+        }
+    | '**' a=NAME { _PyAST_ParamSpec(a->v.Name.id, EXTRA) }
+
+type_param_bound[expr_ty]: ":" e=expression { e }
+
 # EXPRESSIONS
 # -----------
 

Include/cpython/funcobject.h

@@ -41,6 +41,7 @@ typedef struct {
     PyObject *func_weakreflist; /* List of weak references */
     PyObject *func_module;      /* The __module__ attribute, can be anything */
     PyObject *func_annotations; /* Annotations, a dict or NULL */
+    PyObject *func_typeparams;  /* Tuple of active type variables or NULL */
     vectorcallfunc vectorcall;
     /* Version number for use by specializer.
      * Can set to non-zero when we want to specialize.