Link only the bootstrap modules into the build helper programs

Programs/_freeze_module and _bootstrap_python were linked with
$(LIBRARY_OBJS_OMIT_FROZEN), i.e. every static module from all Setup
files (Setup.local, Setup.stdlib with MODULE_BUILDTYPE=static, ...).
That makes it impossible for a builtin module to depend on anything the
helpers produce: a frozen module header, Modules/getpath.o, or generated
sources. A Setup.local module including a header generated by
$(FREEZE_MODULE) is a dependency cycle ("Circular ... dependency
dropped"), and one referencing a getpath.o symbol fails to link, since
_freeze_module links Modules/getpath_noop.o instead. CPython itself
needed a workaround for the latter: a stub of
_Py_Get_Getpath_CodeObject() in getpath_noop.c for _testinternalcapi
in MODULE_BUILDTYPE=static builds.

Mirror what PCbuild/_freeze_module.vcxproj already does on Windows
(a fixed source list plus PC/config_minimal.c): link the helpers with
the core objects plus the modules of Modules/Setup.bootstrap only.

* makesetup: new "-b Setup" option marking a Setup file as the bootstrap
  modules. Their objects and libraries are substituted for
  _BOOTSTRAP_MODOBJS_ / _BOOTSTRAP_MODLIBS_, and a second table,
  config_bootstrap.c, is generated with only those modules. A bootstrap
  module overridden by an earlier rule (Setup.local) keeps the
  overriding static module for the helpers too.
* Makefile.pre.in: BOOTSTRAP_LIBRARY_OBJS (core + Modules/config_bootstrap.o
  + $(BOOTSTRAP_MODOBJS)) replaces LIBRARY_OBJS_OMIT_FROZEN in the
  _freeze_module and _bootstrap_python links. getbuildinfo gets a
  separate object for the helpers, as its prerequisites include
  $(MODOBJS).
* configure.ac / configure: pass -b Modules/Setup.bootstrap and move
  config_bootstrap.c into Modules/ (configure hand-edited in sync).
* Modules/getpath_noop.c: drop the now unnecessary stub.
* Tools/c-analyzer: whitelist _PyImport_Inittab in the generated
  Modules/config_bootstrap.c, as for Modules/config.c.

The final libpython/python link is unchanged.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YD8kPnXaAMJZk2LvSHPXYA

Author: itamaro

.gitignore

@@ -102,6 +102,7 @@ Modules/Setup.config
 Modules/Setup.local
 Modules/Setup.stdlib
 Modules/config.c
+Modules/config_bootstrap.c
 Modules/ld_so_aix
 Programs/_freeze_module
 Programs/_testembed

Makefile.pre.in

@@ -25,6 +25,13 @@ MODSHARED_NAMES=   _MODSHARED_NAMES_
 MODDISABLED_NAMES= _MODDISABLED_NAMES_
 MODOBJS=           _MODOBJS_
 MODLIBS=           _MODLIBS_
+# Objects and libraries of the bootstrap modules (Modules/Setup.bootstrap)
+# only. These are the only static modules linked into the build helper
+# programs (Programs/_freeze_module, _bootstrap_python), so that other
+# builtin modules (Modules/Setup.local, MODULE_BUILDTYPE=static) may depend
+# on products of those helpers (frozen modules, getpath).
+BOOTSTRAP_MODOBJS= _BOOTSTRAP_MODOBJS_
+BOOTSTRAP_MODLIBS= _BOOTSTRAP_MODLIBS_
 
 # === Variables set by configure
 VERSION=	@VERSION@
@@ -359,11 +366,14 @@ COVERAGE_REPORT_OPTIONS=--rc lcov_branch_coverage=1 --branch-coverage --title "C
 
 ##########################################################################
 # Modules
-MODULE_OBJS=	\
-		Modules/config.o \
+MODULE_OBJS_COMMON=	\
 		Modules/main.o \
 		Modules/gcmodule.o
 
+MODULE_OBJS=	\
+		Modules/config.o \
+		$(MODULE_OBJS_COMMON)
+
 IO_H=		Modules/_io/_iomodule.h
 
 IO_OBJS=	\
@@ -614,6 +624,19 @@ LIBRARY_OBJS=	\
 		Modules/getpath.o \
 		Python/frozen.o
 
+# objects that get linked into the build helper programs
+# (Programs/_freeze_module, _bootstrap_python): the core, plus the bootstrap
+# modules only (see BOOTSTRAP_MODOBJS). Does not include frozen modules nor
+# getpath, which the helpers are used to build.
+BOOTSTRAP_LIBRARY_OBJS=	\
+		Modules/getbuildinfo_bootstrap.o \
+		$(PARSER_OBJS) \
+		$(OBJECT_OBJS) \
+		$(PYTHON_OBJS) \
+		Modules/config_bootstrap.o \
+		$(MODULE_OBJS_COMMON) \
+		$(BOOTSTRAP_MODOBJS)
+
 LINK_PYTHON_OBJS=@LINK_PYTHON_OBJS@
 
 ##########################################################################
@@ -1613,7 +1636,7 @@ Modules/Setup.bootstrap: $(srcdir)/Modules/Setup.bootstrap.in config.status
 Modules/Setup.stdlib: $(srcdir)/Modules/Setup.stdlib.in config.status
 	./config.status $@
 
-Makefile Modules/config.c: Makefile.pre \
+Makefile Modules/config.c Modules/config_bootstrap.c: Makefile.pre \
 				$(srcdir)/Modules/config.c.in \
 				$(MAKESETUP) \
 				$(srcdir)/Modules/Setup \
@@ -1624,9 +1647,9 @@ Makefile Modules/config.c: Makefile.pre \
 				-s Modules \
 				Modules/Setup.local \
 				Modules/Setup.stdlib \
-				Modules/Setup.bootstrap \
+				-b Modules/Setup.bootstrap \
 				$(srcdir)/Modules/Setup
-	@mv config.c Modules
+	@mv config.c config_bootstrap.c Modules
 	@echo "The Makefile was updated, you may need to re-run make."
 
 .PHONY: regen-test-frozenmain
@@ -1661,9 +1684,9 @@ BOOTSTRAP_HEADERS = \
 
 Programs/_bootstrap_python.o: Programs/_bootstrap_python.c $(BOOTSTRAP_HEADERS) $(PYTHON_HEADERS)
 
-_bootstrap_python: $(LIBRARY_OBJS_OMIT_FROZEN) Programs/_bootstrap_python.o Modules/getpath.o Modules/Setup.local
-	$(LINKCC) $(PY_LDFLAGS_NOLTO) -o $@ $(LIBRARY_OBJS_OMIT_FROZEN) \
-		Programs/_bootstrap_python.o Modules/getpath.o $(LIBS) $(MODLIBS) $(SYSLIBS)
+_bootstrap_python: $(BOOTSTRAP_LIBRARY_OBJS) Programs/_bootstrap_python.o Modules/getpath.o Modules/Setup.local
+	$(LINKCC) $(PY_LDFLAGS_NOLTO) -o $@ $(BOOTSTRAP_LIBRARY_OBJS) \
+		Programs/_bootstrap_python.o Modules/getpath.o $(LIBS) $(BOOTSTRAP_MODLIBS) $(SYSLIBS)
 	# Dummy pybuilddir.txt  is needed for _bootstrap_python to be runnable
 	@echo "none" > ./pybuilddir.txt
 
@@ -1681,6 +1704,9 @@ _bootstrap_python: $(LIBRARY_OBJS_OMIT_FROZEN) Programs/_bootstrap_python.o Modu
 #
 # Standard build process:
 # 1) compile minimal core objects for Py_Compile*() and PyMarshal_Write*().
+#    Only the bootstrap modules (Modules/Setup.bootstrap) are part of these
+#    objects (see BOOTSTRAP_LIBRARY_OBJS), so other builtin modules may
+#    depend on the output of the following steps.
 # 2) build Programs/_freeze_module binary.
 # 3) create frozen module headers for importlib and getpath.
 # 4) build _bootstrap_python binary.
@@ -1753,8 +1779,8 @@ Programs/_freeze_module.o: Programs/_freeze_module.c Makefile
 
 Modules/getpath_noop.o: $(srcdir)/Modules/getpath_noop.c Makefile
 
-Programs/_freeze_module: Programs/_freeze_module.o Modules/getpath_noop.o $(LIBRARY_OBJS_OMIT_FROZEN)
-	$(LINKCC) $(PY_CORE_LDFLAGS) -o $@ Programs/_freeze_module.o Modules/getpath_noop.o $(LIBRARY_OBJS_OMIT_FROZEN) $(LIBS) $(MODLIBS) $(SYSLIBS)
+Programs/_freeze_module: Programs/_freeze_module.o Modules/getpath_noop.o $(BOOTSTRAP_LIBRARY_OBJS)
+	$(LINKCC) $(PY_CORE_LDFLAGS) -o $@ Programs/_freeze_module.o Modules/getpath_noop.o $(BOOTSTRAP_LIBRARY_OBJS) $(LIBS) $(BOOTSTRAP_MODLIBS) $(SYSLIBS)
 
 # We manually freeze getpath.py rather than through freeze_modules
 Python/frozen_modules/getpath.h: Modules/getpath.py $(FREEZE_MODULE_BOOTSTRAP_DEPS)
@@ -1907,11 +1933,24 @@ Modules/getbuildinfo.o: $(PARSER_OBJS) \
 		$(MODOBJS) \
 		$(DTRACE_OBJS) \
 		$(srcdir)/Modules/getbuildinfo.c
-	$(CC) -c $(PY_CORE_CFLAGS) \
+	$(CC) -c $(PY_CORE_CFLAGS) $(GETBUILDINFO_CFLAGS) \
+	      -o $@ $(srcdir)/Modules/getbuildinfo.c
+
+# Separate object for the build helper programs: it must not depend on
+# $(MODOBJS), which may in turn depend on the helpers' output.
+Modules/getbuildinfo_bootstrap.o: $(PARSER_OBJS) \
+		$(OBJECT_OBJS) \
+		$(PYTHON_OBJS) \
+		$(MODULE_OBJS_COMMON) \
+		$(BOOTSTRAP_MODOBJS) \
+		$(srcdir)/Modules/getbuildinfo.c
+	$(CC) -c $(PY_CORE_CFLAGS) $(GETBUILDINFO_CFLAGS) \
+	      -o $@ $(srcdir)/Modules/getbuildinfo.c
+
+GETBUILDINFO_CFLAGS= \
 	      -DGITVERSION="\"`LC_ALL=C $(GITVERSION)`\"" \
 	      -DGITTAG="\"`LC_ALL=C $(GITTAG)`\"" \
-	      -DGITBRANCH="\"`LC_ALL=C $(GITBRANCH)`\"" \
-	      -o $@ $(srcdir)/Modules/getbuildinfo.c
+	      -DGITBRANCH="\"`LC_ALL=C $(GITBRANCH)`\""
 
 Modules/getpath.o: $(srcdir)/Modules/getpath.c Python/frozen_modules/getpath.h Makefile $(PYTHON_HEADERS)
 	$(CC) -c $(PY_CORE_CFLAGS) -DPYTHONPATH='"$(PYTHONPATH)"' \
@@ -2279,7 +2318,7 @@ regen-slots: Python/slots.toml
 	$(PYTHON_FOR_REGEN) $(srcdir)/Tools/build/generate_slots.py \
 		--generate-all
 
-$(LIBRARY_OBJS) $(MODOBJS) Programs/python.o $(PLATFORM_MAIN_OBJS): $(PYTHON_HEADERS)
+$(LIBRARY_OBJS) $(MODOBJS) Modules/config_bootstrap.o Programs/python.o $(PLATFORM_MAIN_OBJS): $(PYTHON_HEADERS)
 
 
 ######################################################################
@@ -3365,7 +3404,7 @@ clean: clean-profile clean-jit-stencils
 clobber: clean
 	-rm -f $(BUILDPYTHON) $(LIBRARY) $(LDLIBRARY) $(DLLLIBRARY) \
 		tags TAGS \
-		config.cache config.log pyconfig.h Modules/config.c
+		config.cache config.log pyconfig.h Modules/config.c Modules/config_bootstrap.c
 	-rm -rf build platform
 	-rm -rf $(PYTHONFRAMEWORKDIR)
 	-rm -rf Platforms/Apple/iOS/Frameworks

Modules/getpath_noop.c

@@ -1,21 +1,10 @@
 /* Implements the getpath API for compiling with no functionality */
 
 #include "Python.h"
-#include "pycore_initconfig.h"    // _Py_Get_Getpath_CodeObject()
 #include "pycore_pathconfig.h"    // _PyConfig_InitPathConfig()
 
 PyStatus
 _PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
 {
     return PyStatus_Error("path configuration is unsupported");
 }
-
-/* Used by _testinternalcapi, which is linked into Programs/_freeze_module
-   when extension modules are built in (MODULE_BUILDTYPE=static). */
-PyObject *
-_Py_Get_Getpath_CodeObject(void)
-{
-    PyErr_SetString(PyExc_RuntimeError,
-                    "path configuration is unsupported");
-    return NULL;
-}

Modules/makesetup

@@ -4,17 +4,22 @@ set -e
 # Convert templates into Makefile and config.c, based on the module
 # definitions found in the file Setup.
 #
-# Usage: makesetup [-s dir] [-c file] [-m file] [Setup] ... [-n [Setup] ...]
+# Usage: makesetup [-s dir] [-c file] [-m file] [Setup] ... [-b Setup] ...
+#                  [-n [Setup] ...]
 #
 # Options:
 # -s directory: alternative source directory (default .)
 # -l directory: library source directory (default derived from $0)
 # -c file:      alternative config.c template (default $libdir/config.c.in)
-# -c -:         don't write config.c
+# -c -:         don't write config.c (nor config_bootstrap.c)
 # -m file:      alternative Makefile template (default ./Makefile.pre)
 # -m -:         don't write Makefile
 #
 # Remaining arguments are one or more Setup files (default ./Setup).
+# The Setup file following a -b option holds the *bootstrap* modules:
+# the static modules that the build helper programs (_freeze_module,
+# _bootstrap_python) are linked with. They are also regular modules of
+# the final build.
 # Setup files after a -n option are used for their variables, modules
 # and libraries but not for their .o files.
 #
@@ -28,6 +33,9 @@ set -e
 #   + insert 'extern PyObject* PyInit_<module>(void);' before MARKER 1
 #   + insert '{"<module>", PyInit_<module>},' before MARKER 2
 #
+# Copying config.c.in to config_bootstrap.c (only with a -b Setup file):
+# - same as config.c, but only for the modules of the -b Setup file
+#
 # Copying Makefile.pre to Makefile:
 # - insert an identifying comment at the start
 # - replace _MODBUILT_NAMES_ by the list of *static* and *shared* modules
@@ -37,6 +45,8 @@ set -e
 # - replace _MODOBJS_ by the list of objects from Setup (except for
 #   Setup files after a -n option)
 # - replace _MODLIBS_ by the list of libraries from Setup
+# - replace _BOOTSTRAP_MODOBJS_ and _BOOTSTRAP_MODLIBS_ by the objects and
+#   libraries of the -b Setup file
 # - for each object file mentioned in Setup, append a rule
 #   '<file>.o: <file>.c; <build commands>' to the end of the Makefile
 # - for each module mentioned in Setup, append a rule
@@ -47,13 +57,14 @@ set -e
 # Loop over command line options
 usage='
 usage: makesetup [-s srcdir] [-l libdir] [-c config.c.in] [-m Makefile.pre]
-                 [Setup] ... [-n [Setup] ...]'
+                 [Setup] ... [-b Setup] ... [-n [Setup] ...]'
 srcdir='.'
 libdir=''
 config=''
 makepre=''
 noobjects=''
 doconfig=yes
+bootstrap=
 while :
 do
 	case $1 in
@@ -93,7 +104,8 @@ do
 	echo ''  # Add a linebreak so we don't choke on files missing EOL.
 	case $i in
 	-n)	echo '*noobjects*';;
-	*)	echo '*doconfig*'; cat "$i";;
+	-b)	echo '*bootstrap*';;
+	*)	echo '*doconfig*'; cat "$i"; echo ''; echo '*nobootstrap*';;
 	esac
 done |
 sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
@@ -114,6 +126,10 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 	LIBS=
 	LOCALLIBS=
 	BASELIBS=
+	BOOTMODS=
+	BOOTOBJS=
+	BOOTLIBS=
+	havebootstrap=
 	while read line
 	do
 		# to handle backslashes for sh's that don't automatically
@@ -136,6 +152,8 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 			noobjects=yes;
 			continue;;
 		'*doconfig*')	doconfig=yes; continue;;
+		'*bootstrap*')	bootstrap=yes; havebootstrap=yes; continue;;
+		'*nobootstrap*')	bootstrap=; continue;;
 		'*static*')	doconfig=yes; continue;;
 		'*noconfig*')	doconfig=no; continue;;
 		'*shared*')	doconfig=no; continue;;
@@ -204,6 +222,16 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 				# Detected multiple rules for a module, first rule wins. This
 				# allows users to disable modules in Setup.local.
 				echo 1>&2 "maksetup: '$mod' was handled by previous rule."
+				case $bootstrap in
+				yes)
+					# A bootstrap module overridden by an earlier rule
+					# (e.g. in Setup.local): the build helpers get the
+					# overriding static module, if any.
+					eval "BOOTMODS=\"\$BOOTMODS \${STATICMOD_$mod}\""
+					eval "BOOTOBJS=\"\$BOOTOBJS \${STATICOBJS_$mod}\""
+					eval "BOOTLIBS=\"\$BOOTLIBS \${STATICLIBS_$mod}\""
+					;;
+				esac
 				continue 2;;
 			esac
 			CONFIGURED="$CONFIGURED,${mod},"
@@ -213,6 +241,12 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 			LIBS="$LIBS $libs"
 			MODS="$MODS $mods"
 			BUILT="$BUILT $mods"
+			case $bootstrap in
+			yes)
+				BOOTLIBS="$BOOTLIBS $libs"
+				BOOTMODS="$BOOTMODS $mods"
+				;;
+			esac
 			;;
 		no)
 			BUILT="$BUILT $mods"
@@ -265,7 +299,20 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 			echo "$rule" >>$rulesf
 		done
 		case $doconfig in
-		yes)	OBJS="$OBJS $objs";;
+		yes)
+			OBJS="$OBJS $objs"
+			case $bootstrap in
+			yes)	BOOTOBJS="$BOOTOBJS $objs";;
+			esac
+			# Remember static modules so that a later bootstrap rule
+			# for the same module can pick them up (see above).
+			for mod in $mods
+			do
+				eval "STATICMOD_$mod='$mod'"
+				eval "STATICOBJS_$mod='$objs'"
+				eval "STATICLIBS_$mod='$libs'"
+			done
+			;;
 		esac
 		for mod in $mods
 		do
@@ -295,24 +342,31 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 	DEFS="BASEMODLIBS=$BASELIBS$NL$DEFS"
 	DEFS="LOCALMODLIBS=$LOCALLIBS$NL$DEFS"
 
-	EXTDECLS=
-	INITBITS=
-	for mod in $MODS
-	do
-		EXTDECLS="${EXTDECLS}extern PyObject* PyInit_$mod(void);$NL"
-		INITBITS="${INITBITS}    {\"$mod\", PyInit_$mod},$NL"
-	done
-
-
-	case $config in
-	-)  ;;
-	*)  sed -e "
+	# Generate a config.c from the template for the given modules
+	genconfig() {
+		out=$1; shift
+		EXTDECLS=
+		INITBITS=
+		for mod
+		do
+			EXTDECLS="${EXTDECLS}extern PyObject* PyInit_$mod(void);$NL"
+			INITBITS="${INITBITS}    {\"$mod\", PyInit_$mod},$NL"
+		done
+		sed -e "
 		1i$NL/* Generated automatically from $config by makesetup. */
 		/MARKER 1/i$NL$EXTDECLS
 
 		/MARKER 2/i$NL$INITBITS
 
-		" $config >config.c
+		" $config >$out
+	}
+
+	case $config in
+	-)  ;;
+	*)  genconfig config.c $MODS
+	    case $havebootstrap in
+	    yes)  genconfig config_bootstrap.c $BOOTMODS;;
+	    esac
 	    ;;
 	esac
 
@@ -331,6 +385,9 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 		echo "s%_MODBUILT_NAMES_%$BUILT%" >>$sedf
 		echo "s%_MODSHARED_NAMES_%$BUILT_SHARED%" >>$sedf
 		echo "s%_MODDISABLED_NAMES_%$DISABLED%" >>$sedf
+		# _BOOTSTRAP_* first: _MODOBJS_ is a substring of _BOOTSTRAP_MODOBJS_
+		echo "s%_BOOTSTRAP_MODOBJS_%$BOOTOBJS%" >>$sedf
+		echo "s%_BOOTSTRAP_MODLIBS_%$BOOTLIBS%" >>$sedf
 		echo "s%_MODOBJS_%$OBJS%" >>$sedf
 		echo "s%_MODLIBS_%$LIBS%" >>$sedf
 		echo "/Definitions added by makesetup/r $sedr" >>$sedf

Tools/c-analyzer/cpython/ignored.tsv

@@ -314,6 +314,7 @@ Modules/cmathmodule.c	-	sinh_special_values	-
 Modules/cmathmodule.c	-	sqrt_special_values	-
 Modules/cmathmodule.c	-	tanh_special_values	-
 Modules/config.c	-	_PyImport_Inittab	-
+Modules/config_bootstrap.c	-	_PyImport_Inittab	-
 Modules/faulthandler.c	-	faulthandler_handlers	-
 Modules/getnameinfo.c	-	gni_afdl	-
 Modules/hmacmodule.c	-	py_hmac_static_hinfo	-