gh-115119: Removed bundled copy of the libmpdec

.github/workflows/posix-deps-apt.sh

@@ -27,7 +27,7 @@ apt-get -yq --no-install-recommends install \
  zlib1g-dev
 
 # Workaround missing libmpdec-dev on ubuntu 24.04 by building mpdecimal
-# from source. ppa:ondrej/php (launchpad.net) are unreliable
+# from source. ppa:ondrej/php (launchpad.net) are unreliable
 # (https://status.canonical.com) so fetch the tarball directly
 # from the upstream host.
 # https://www.bytereef.org/mpdecimal/

Doc/tools/removed-ids.txt

@@ -6,6 +6,9 @@ c-api/file.html: deprecated-api
 
 library/asyncio-task.html: terminating-a-task-group
 
+# Removed libmpdec
+using/configure.html: cmdoption-with-system-libmpdec
+
 # Removed APIs
 library/symtable.html: symtable.Class.get_methods
-library/sys.html: sys._enablelegacywindowsfsencoding
+library/sys.html: sys._enablelegacywindowsfsencoding

Doc/using/configure.rst

@@ -112,7 +112,6 @@ Dependencies to build optional modules are:
 
 .. [1] If *libmpdec* is not available, the :mod:`decimal` module will use
  a pure-Python implementation.
- See :option:`--with-system-libmpdec` for details.
 .. [2] See :option:`--with-readline` for choosing the backend for the
  :mod:`readline` module.
 .. [3] The :mod:`uuid` module uses ``_uuid`` to generate "safe" UUIDs.
@@ -553,11 +552,6 @@ Options for third-party dependencies
  C compiler and linker flags for ``libmpdec``, used by :mod:`decimal` module,
  overriding ``pkg-config``.
 
- .. note::
-
- These environment variables have no effect unless
- :option:`--with-system-libmpdec` is specified.
-
 .. option:: LIBLZMA_CFLAGS
 .. option:: LIBLZMA_LIBS
 
@@ -1067,29 +1061,6 @@ Libraries options
  Build the :mod:`!pyexpat` module using an installed ``expat`` library
  (default is no).
 
-.. option:: --with-system-libmpdec
-
- Build the ``_decimal`` extension module using an installed ``mpdecimal``
- library, see the :mod:`decimal` module (default is yes).
-
- .. versionadded:: 3.3
-
- .. versionchanged:: 3.13
- Default to using the installed ``mpdecimal`` library.
-
- .. versionchanged:: 3.15
-
- A bundled copy of the library will no longer be selected
- implicitly if an installed ``mpdecimal`` library is not found.
- In Python 3.15 only, it can still be selected explicitly using
- ``--with-system-libmpdec=no`` or ``--without-system-libmpdec``.
-
- .. deprecated-removed:: 3.13 3.16
- A copy of the ``mpdecimal`` library sources will no longer be distributed
- with Python 3.16.
-
- .. seealso:: :option:`LIBMPDEC_CFLAGS` and :option:`LIBMPDEC_LIBS`.
-
 .. option:: --with-readline=readline|editline
 
  Designate a backend library for the :mod:`readline` module.

Doc/whatsnew/3.13.rst

@@ -2597,7 +2597,7 @@ Build Changes
 
  .. _mimalloc library: https://github.com/microsoft/mimalloc/
 
-* The :file:`configure` option :option:`--with-system-libmpdec`
+* The :file:`configure` option :option:`!--with-system-libmpdec`
  now defaults to ``yes``.
  The bundled copy of ``libmpdec`` will be removed in Python 3.16.
 

Doc/whatsnew/3.15.rst

@@ -2626,7 +2626,7 @@ Build changes
 =============
 
 * Removed implicit fallback to the bundled copy of the ``libmpdec`` library.
- Now this should be explicitly enabled with :option:`--with-system-libmpdec`
+ Now this should be explicitly enabled with :option:`!--with-system-libmpdec`
  set to ``no`` or with :option:`!--without-system-libmpdec`.
  (Contributed by Sergey B Kirpichev in :gh:`115119`.)
 

Doc/whatsnew/3.16.rst

@@ -191,6 +191,17 @@ that may require changes to your code.
 Build changes
 =============
 
+* Remove the bundled copy of the libmpdec_ decimal library from the CPython source tree
+ to simplify maintenence and updates. The :mod:`decimal` module will now
+ unconditionally use the system's libmpdec decimal library. Also remove the
+ now unused :option:`!--with-system-libmpdec` :program:`configure` flag.
+ This change has no impact on binary releases of Python, which have been
+ built against a separate copy of libmpdec for the past several releases.
+
+ (Contributed by Sergey B Kirpichev in :gh:`115119`.)
+
+ .. _libmpdec: https://www.bytereef.org/mpdecimal/
+
 
 C API changes
 =============

Mac/BuildScript/build-installer.py

@@ -1158,7 +1158,6 @@ def buildPython():
  print(" NOTE: --with-mimalloc=no pending resolution of weak linking issues")
  runCommand("%s -C --enable-framework --enable-universalsdk=/ "
  "--with-mimalloc=no "
- "--with-system-libmpdec "
  "--with-universal-archs=%s "
  "%s "
  "%s "

Makefile.pre.in

@@ -231,7 +231,6 @@ RUNSHARED= @RUNSHARED@
 ENSUREPIP= @ENSUREPIP@
 
 # Internal static libraries
-LIBMPDEC_A= Modules/_decimal/libmpdec/libmpdec.a
 LIBEXPAT_A= Modules/expat/libexpat.a
 
 # HACL* build configuration
@@ -606,45 +605,6 @@ LINK_PYTHON_OBJS=@LINK_PYTHON_OBJS@
 DTRACE_DEPS = \
 	Python/ceval.o Python/gc.o Python/import.o Python/sysmodule.o
 
-##########################################################################
-# decimal's libmpdec
-
-LIBMPDEC_OBJS= \
- Modules/_decimal/libmpdec/basearith.o \
- Modules/_decimal/libmpdec/constants.o \
- Modules/_decimal/libmpdec/context.o \
- Modules/_decimal/libmpdec/convolute.o \
- Modules/_decimal/libmpdec/crt.o \
- Modules/_decimal/libmpdec/difradix2.o \
- Modules/_decimal/libmpdec/fnt.o \
- Modules/_decimal/libmpdec/fourstep.o \
- Modules/_decimal/libmpdec/io.o \
- Modules/_decimal/libmpdec/mpalloc.o \
- Modules/_decimal/libmpdec/mpdecimal.o \
- Modules/_decimal/libmpdec/numbertheory.o \
- Modules/_decimal/libmpdec/sixstep.o \
- Modules/_decimal/libmpdec/transpose.o
- # _decimal does not use signaling API
- # Modules/_decimal/libmpdec/mpsignal.o
-
-LIBMPDEC_HEADERS= \
- $(srcdir)/Modules/_decimal/libmpdec/basearith.h \
- $(srcdir)/Modules/_decimal/libmpdec/bits.h \
- $(srcdir)/Modules/_decimal/libmpdec/constants.h \
- $(srcdir)/Modules/_decimal/libmpdec/convolute.h \
- $(srcdir)/Modules/_decimal/libmpdec/crt.h \
- $(srcdir)/Modules/_decimal/libmpdec/difradix2.h \
- $(srcdir)/Modules/_decimal/libmpdec/fnt.h \
- $(srcdir)/Modules/_decimal/libmpdec/fourstep.h \
- $(srcdir)/Modules/_decimal/libmpdec/io.h \
- $(srcdir)/Modules/_decimal/libmpdec/mpalloc.h \
- $(srcdir)/Modules/_decimal/libmpdec/mpdecimal.h \
- $(srcdir)/Modules/_decimal/libmpdec/numbertheory.h \
- $(srcdir)/Modules/_decimal/libmpdec/sixstep.h \
- $(srcdir)/Modules/_decimal/libmpdec/transpose.h \
- $(srcdir)/Modules/_decimal/libmpdec/typearith.h \
- $(srcdir)/Modules/_decimal/libmpdec/umodarith.h
-
 ##########################################################################
 # pyexpat's expat library
 
@@ -962,7 +922,6 @@ coverage-lcov:
 	@lcov $(COVERAGE_LCOV_OPTIONS) --remove $(COVERAGE_INFO) \
  '*/Modules/_hacl/*' \
  '*/Modules/_ctypes/libffi*/*' \
- '*/Modules/_decimal/libmpdec/*' \
  '*/Modules/expat/*' \
  '*/Modules/xx*.c' \
  '*/Python/pyfpe.c' \
@@ -1471,60 +1430,6 @@ PYTHON_HEADERS= \
  \
  $(srcdir)/Python/stdlib_module_names.h
 
-##########################################################################
-# Build static libmpdec.a
-LIBMPDEC_CFLAGS=@LIBMPDEC_CFLAGS@ $(PY_STDMODULE_CFLAGS) $(CCSHARED)
-
-# "%.o: %c" is not portable
-Modules/_decimal/libmpdec/basearith.o: $(srcdir)/Modules/_decimal/libmpdec/basearith.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/basearith.c
-
-Modules/_decimal/libmpdec/constants.o: $(srcdir)/Modules/_decimal/libmpdec/constants.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/constants.c
-
-Modules/_decimal/libmpdec/context.o: $(srcdir)/Modules/_decimal/libmpdec/context.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/context.c
-
-Modules/_decimal/libmpdec/convolute.o: $(srcdir)/Modules/_decimal/libmpdec/convolute.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/convolute.c
-
-Modules/_decimal/libmpdec/crt.o: $(srcdir)/Modules/_decimal/libmpdec/crt.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/crt.c
-
-Modules/_decimal/libmpdec/difradix2.o: $(srcdir)/Modules/_decimal/libmpdec/difradix2.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/difradix2.c
-
-Modules/_decimal/libmpdec/fnt.o: $(srcdir)/Modules/_decimal/libmpdec/fnt.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/fnt.c
-
-Modules/_decimal/libmpdec/fourstep.o: $(srcdir)/Modules/_decimal/libmpdec/fourstep.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/fourstep.c
-
-Modules/_decimal/libmpdec/io.o: $(srcdir)/Modules/_decimal/libmpdec/io.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/io.c
-
-Modules/_decimal/libmpdec/mpalloc.o: $(srcdir)/Modules/_decimal/libmpdec/mpalloc.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/mpalloc.c
-
-Modules/_decimal/libmpdec/mpdecimal.o: $(srcdir)/Modules/_decimal/libmpdec/mpdecimal.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/mpdecimal.c
-
-Modules/_decimal/libmpdec/mpsignal.o: $(srcdir)/Modules/_decimal/libmpdec/mpsignal.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/mpsignal.c
-
-Modules/_decimal/libmpdec/numbertheory.o: $(srcdir)/Modules/_decimal/libmpdec/numbertheory.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/numbertheory.c
-
-Modules/_decimal/libmpdec/sixstep.o: $(srcdir)/Modules/_decimal/libmpdec/sixstep.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/sixstep.c
-
-Modules/_decimal/libmpdec/transpose.o: $(srcdir)/Modules/_decimal/libmpdec/transpose.c $(LIBMPDEC_HEADERS) $(PYTHON_HEADERS)
-	$(CC) -c $(LIBMPDEC_CFLAGS) -o $@ $(srcdir)/Modules/_decimal/libmpdec/transpose.c
-
-$(LIBMPDEC_A): $(LIBMPDEC_OBJS)
-	-rm -f $@
-	$(AR) $(ARFLAGS) $@ $(LIBMPDEC_OBJS)
-
 ##########################################################################
 # Build static libexpat.a
 LIBEXPAT_CFLAGS=@LIBEXPAT_CFLAGS@ $(PY_STDMODULE_CFLAGS) $(CCSHARED)
@@ -3501,7 +3406,6 @@ MODULE_UNICODEDATA_DEPS=$(srcdir)/Modules/unicodedata_db.h $(srcdir)/Modules/uni
 MODULE__CTYPES_DEPS=$(srcdir)/Modules/_ctypes/ctypes.h
 MODULE__CTYPES_TEST_DEPS=$(srcdir)/Modules/_ctypes/_ctypes_test_generated.c.h
 MODULE__CTYPES_MALLOC_CLOSURE=@MODULE__CTYPES_MALLOC_CLOSURE@
-MODULE__DECIMAL_DEPS=@LIBMPDEC_INTERNAL@
 MODULE__ELEMENTTREE_DEPS=$(srcdir)/Modules/pyexpat.c @LIBEXPAT_INTERNAL@
 MODULE__HASHLIB_DEPS=$(srcdir)/Modules/hashlib.h
 MODULE__IO_DEPS=$(srcdir)/Modules/_io/_iomodule.h

Misc/NEWS.d/3.12.0a2.rst

@@ -957,7 +957,7 @@ Fix ``make regen-test-levenshtein`` for out-of-tree builds.
 .. nonce: eVXGEx
 .. section: Build
 
-Don't use vendored ``libmpdec`` headers if :option:`--with-system-libmpdec`
+Don't use vendored ``libmpdec`` headers if :option:`!--with-system-libmpdec`
 is passed to :program:`configure`. Don't use vendored ``libexpat`` headers
 if :option:`--with-system-expat` is passed to :program:`configure`.
 

Misc/NEWS.d/3.13.0b1.rst

@@ -1429,7 +1429,7 @@ script) without specifying a value for ``UseTIER2``.
 .. nonce: LT27pF
 .. section: Build
 
-The :file:`configure` option :option:`--with-system-libmpdec` now defaults
+The :file:`configure` option :option:`!--with-system-libmpdec` now defaults
 to ``yes``. The bundled copy of ``libmpdecimal`` will be removed in Python
 3.15.
 
@@ -1470,7 +1470,7 @@ Increase WASI stack size from 512 KiB to 8 MiB and the initial memory from
 .. section: Build
 
 :program:`configure` now uses :program:`pkg-config` to detect :mod:`decimal`
-dependencies if the :option:`--with-system-libmpdec` option is given.
+dependencies if the :option:`!--with-system-libmpdec` option is given.
 
 ..
 

Misc/NEWS.d/3.15.0a1.rst

@@ -6395,7 +6395,7 @@ Add support for configuring compiler flags for the JIT with ``CFLAGS_JIT``
 .. section: Build
 
 Removed implicit fallback to the bundled copy of the ``libmpdec`` library.
-Now this should be explicitly enabled via :option:`--with-system-libmpdec`
+Now this should be explicitly enabled via :option:`!--with-system-libmpdec`
 set to ``no`` or :option:`!--without-system-libmpdec`. Patch by Sergey B
 Kirpichev.
 

Misc/NEWS.d/next/Build/2025-05-13-12-38-26.gh-issue-115119.7n0nx3.rst

@@ -0,0 +1,2 @@
+Removed bundled copy of the libmpdec, use system library if it's available.
+Patch by Sergey B Kirpichev.