bpo-45847: Port _tkinter to PY_STDLIB_MOD (GH-31698)

- Remove ``--with-tclk-*`` options from `configure`
- Use pkg-config to detect `_tkinter` dependencies (Tcl/Tk, X11)
- Manual override via environment variables `TCLTK_CFLAGS` and `TCLTK_LIBS`

Author: Erlend Egeberg Aasland

Doc/using/configure.rst

@@ -404,14 +404,6 @@ Libraries options
 
    .. versionadded:: 3.10
 
-.. cmdoption:: --with-tcltk-includes='-I...'
-
-   Override search for Tcl and Tk include files.
-
-.. cmdoption:: --with-tcltk-libs='-L...'
-
-   Override search for Tcl and Tk libraries.
-
 .. cmdoption:: --with-libm=STRING
 
    Override ``libm`` math library to *STRING* (default is system-dependent).

Doc/whatsnew/3.10.rst

@@ -2019,8 +2019,8 @@ Build Changes
 
 * The ``configure`` script now uses the ``pkg-config`` utility, if available,
   to detect the location of Tcl/Tk headers and libraries.  As before, those
-  locations can be explicitly specified with the :option:`--with-tcltk-includes`
-  and :option:`--with-tcltk-libs` configuration options.
+  locations can be explicitly specified with the ``--with-tcltk-includes``
+  and ``--with-tcltk-libs`` configuration options.
   (Contributed by Manolis Stamatogiannakis in :issue:`42603`.)
 
 * Add :option:`--with-openssl-rpath` option to ``configure`` script. The option

Doc/whatsnew/3.11.rst

@@ -770,11 +770,17 @@ Build Changes
 
 * Build dependencies, compiler flags, and linker flags for most stdlib
   extension modules are now detected by :program:`configure`. libffi, libnsl,
-  libsqlite3, zlib, bzip2, liblzma, libcrypt, and uuid flags are detected by
-  ``pkg-config`` (when available).
+  libsqlite3, zlib, bzip2, liblzma, libcrypt, Tcl/Tk libs, and uuid flags
+  are detected by ``pkg-config`` (when available).
   (Contributed by Christian Heimes and Erlend Egeberg Aasland in
   :issue:`bpo-45847`, :issue:`45747`, and :issue:`45763`.)
 
+  .. note::
+     Use the environment variables ``TCLTK_CFLAGS`` and ``TCLTK_LIBS`` to
+     manually specify the location of Tcl/Tk headers and libraries.
+     The :program:`configure` options ``--with-tcltk-includes`` and
+     ``--with-tcltk-libs`` have been removed.
+
 * CPython now has experimental support for cross compiling to WebAssembly
   platform ``wasm32-emscripten``. The effort is inspired by previous work
   like Pyodide.

Doc/whatsnew/3.9.rst

@@ -1249,7 +1249,7 @@ Build Changes
   of macOS. If a macOS SDK is explicitly configured, by using
   :option:`--enable-universalsdk` or ``-isysroot``, only the SDK itself is
   searched. The default behavior can still be overridden with
-  :option:`--with-tcltk-includes` and :option:`--with-tcltk-libs`.
+  ``--with-tcltk-includes`` and ``--with-tcltk-libs``.
   (Contributed by Ned Deily in :issue:`34956`.)
 
 * Python can now be built for Windows 10 ARM64.

Makefile.pre.in

@@ -302,10 +302,6 @@ _PYTHON_HOST_PLATFORM=@_PYTHON_HOST_PLATFORM@
 BUILD_GNU_TYPE=	@build@
 HOST_GNU_TYPE=	@host@
 
-# Tcl and Tk config info from --with-tcltk-includes and -libs options
-TCLTK_INCLUDES=	@TCLTK_INCLUDES@
-TCLTK_LIBS=	@TCLTK_LIBS@
-
 # The task to run while instrumented when building the profile-opt target.
 # To speed up profile generation, we don't run the full unit test suite
 # by default. The default is "-m test --pgo". To run more tests, use
@@ -736,10 +732,8 @@ sharedmods: $(BUILDPYTHON) pybuilddir.txt @LIBMPDEC_INTERNAL@ @LIBEXPAT_INTERNAL
 	    *) quiet="";; \
 	esac; \
 	echo "$(RUNSHARED) CC='$(CC)' LDSHARED='$(BLDSHARED)' OPT='$(OPT)' \
-		_TCLTK_INCLUDES='$(TCLTK_INCLUDES)' _TCLTK_LIBS='$(TCLTK_LIBS)' \
 		$(PYTHON_FOR_BUILD) $(srcdir)/setup.py $$quiet build"; \
 	$(RUNSHARED) CC='$(CC)' LDSHARED='$(BLDSHARED)' OPT='$(OPT)' \
-		_TCLTK_INCLUDES='$(TCLTK_INCLUDES)' _TCLTK_LIBS='$(TCLTK_LIBS)' \
 		$(PYTHON_FOR_BUILD) $(srcdir)/setup.py $$quiet build
 
 

Modules/Setup.stdlib.in

@@ -150,12 +150,11 @@
 # needs -lcrypt
 @MODULE__HASHLIB_TRUE@_hashlib _hashopenssl.c
 
-# needs -ltk, -ltcl, and sometimes -lX11
-#@MODULE__TKINTER_TRUE@_tkinter _tkinter.c tkappinit.c
-
 # Linux: -luuid, BSD/AIX: libc's uuid_create()
 @MODULE__UUID_TRUE@_uuid _uuidmodule.c
 
+@MODULE__TKINTER_TRUE@_tkinter _tkinter.c tkappinit.c
+
 ############################################################################
 # macOS specific modules