gh-149499: Fixes for 3.16 bump (GH-149500)

Also fixes gh-149507, regenerating `configure` for 3.16.

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Zachary Ware <zach@python.org>

Author: 3 people

Doc/whatsnew/3.16.rst

@@ -106,10 +106,13 @@ module_name
 Removed
 =======
 
-module_name
------------
+sysconfig
+---------
+
+* The :func:`!sysconfig.expand_makefile_vars` function
+  which has been deprecated since Python 3.14.
+  Use the ``vars`` argument of :func:`sysconfig.get_paths` instead.
 
-* TODO
 .. Add removals above alphabetically, not here at the end.
 
 
@@ -156,4 +159,3 @@ Deprecated C APIs
 
 Removed C APIs
 --------------
-

Include/internal/pycore_magic_number.h

@@ -297,9 +297,10 @@ Known values:
     Python 3.15a8 3664 (Fix __qualname__ for __annotate__ functions)
     Python 3.15a8 3665 (Add FOR_ITER_VIRTUAL and GET_ITER specializations)
     Python 3.15b1 3666 (Add SEND_VIRTUAL and SEND_ASYNC_GEN specializations)
+    Python 3.16a0 3700 (Initial version)
 
 
-    Python 3.16 will start with 3700
+    Python 3.17 will start with 3750
 
     Please don't copy-paste the same pre-release tag for new entries above!!!
     You should always use the *upcoming* tag. For example, if 3.12a6 came out
@@ -310,7 +311,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3666
+#define PYC_MAGIC_NUMBER 3700
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \

Lib/sysconfig/__init__.py

@@ -753,41 +753,3 @@ def get_python_version():
 
 def _get_python_version_abi():
     return _PY_VERSION_SHORT + get_config_var("abi_thread")
-
-
-def expand_makefile_vars(s, vars):
-    """Expand Makefile-style variables -- "${foo}" or "$(foo)" -- in
-    'string' according to 'vars' (a dictionary mapping variable names to
-    values).  Variables not present in 'vars' are silently expanded to the
-    empty string.  The variable values in 'vars' should not contain further
-    variable expansions; if 'vars' is the output of 'parse_makefile()',
-    you're fine.  Returns a variable-expanded version of 's'.
-    """
-
-    import warnings
-    warnings.warn(
-        'sysconfig.expand_makefile_vars is deprecated and will be removed in '
-        'Python 3.16. Use sysconfig.get_paths(vars=...) instead.',
-        DeprecationWarning,
-        stacklevel=2,
-    )
-
-    import re
-
-    _findvar1_rx = r"\$\(([A-Za-z][A-Za-z0-9_]*)\)"
-    _findvar2_rx = r"\${([A-Za-z][A-Za-z0-9_]*)}"
-
-    # This algorithm does multiple expansion, so if vars['foo'] contains
-    # "${bar}", it will expand ${foo} to ${bar}, and then expand
-    # ${bar}... and so forth.  This is fine as long as 'vars' comes from
-    # 'parse_makefile()', which takes care of such expansions eagerly,
-    # according to make's variable expansion semantics.
-
-    while True:
-        m = re.search(_findvar1_rx, s) or re.search(_findvar2_rx, s)
-        if m:
-            (beg, end) = m.span()
-            s = s[0:beg] + vars.get(m.group(1)) + s[end:]
-        else:
-            break
-    return s

Misc/NEWS.d/next/Library/2026-05-07-17-35-47.gh-issue-149499.G2ER-R.rst

@@ -0,0 +1,3 @@
+Removed the :func:`!sysconfig.expand_makefile_vars` function which has been
+deprecated since Python 3.14. Use the ``vars`` argument of
+:func:`sysconfig.get_paths` instead.

PC/launcher.c

@@ -1273,6 +1273,7 @@ static PYC_MAGIC magic_values[] = {
     { 3550, 3599, L"3.13" },
     { 3600, 3649, L"3.14" },
     { 3650, 3699, L"3.15" },
+    { 3700, 3749, L"3.16" },
     { 0 }
 };
 

PC/pyconfig.h

@@ -330,21 +330,21 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
                         the linking is explicitly handled */
 #                       if defined(Py_GIL_DISABLED)
 #                       if defined(Py_DEBUG)
-#                               pragma comment(lib,"python315t_d.lib")
+#                               pragma comment(lib,"python316t_d.lib")
 #                       elif defined(Py_LIMITED_API) || defined(Py_TARGET_ABI3T)
 #                               pragma comment(lib,"python3t.lib")
 #                       else
-#                               pragma comment(lib,"python315t.lib")
+#                               pragma comment(lib,"python316t.lib")
 #                       endif /* Py_DEBUG */
 #                       else /* Py_GIL_DISABLED */
 #                       if defined(Py_DEBUG)
-#                               pragma comment(lib,"python315_d.lib")
+#                               pragma comment(lib,"python316_d.lib")
 #                       elif defined(Py_TARGET_ABI3T)
 #                               pragma comment(lib,"python3t.lib")
 #                       elif defined(Py_LIMITED_API)
 #                               pragma comment(lib,"python3.lib")
 #                       else
-#                               pragma comment(lib,"python315.lib")
+#                               pragma comment(lib,"python316.lib")
 #                       endif /* Py_DEBUG */
 #                       endif /* Py_GIL_DISABLED */
 #               endif /* _MSC_VER && !Py_NO_LINK_LIB */